diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/resources/bootstrap/CriterionsBootstrap.java b/navalplanner-business/src/main/java/org/navalplanner/business/resources/bootstrap/CriterionsBootstrap.java
index d481f9e50..7d302863b 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/resources/bootstrap/CriterionsBootstrap.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/resources/bootstrap/CriterionsBootstrap.java
@@ -6,6 +6,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 
+import org.navalplanner.business.common.exceptions.ValidationException;
 import org.navalplanner.business.resources.entities.Criterion;
 import org.navalplanner.business.resources.entities.ICriterionType;
 import org.navalplanner.business.resources.services.CriterionService;
@@ -47,7 +48,11 @@ public class CriterionsBootstrap implements ICriterionsBootstrap {
         for (Entry<ICriterionType<?>, List<Criterion>> entry : typesWithCriterions
                 .entrySet()) {
             for (Criterion criterion : entry.getValue()) {
-                criterionService.createIfNotExists(criterion);
+                try {
+                    criterionService.createIfNotExists(criterion);
+                } catch (ValidationException e) {
+                    e.printStackTrace();
+                }
             }
         }
     }
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/ICriterionDAO.java b/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/ICriterionDAO.java
index 2548c41b4..074382fe2 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/ICriterionDAO.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/ICriterionDAO.java
@@ -1,5 +1,6 @@
 package org.navalplanner.business.resources.daos;
 
+import java.util.List;
 import org.navalplanner.business.common.daos.IGenericDao;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
 import org.navalplanner.business.resources.daos.impl.CriterionDAO;
@@ -13,7 +14,9 @@ public interface ICriterionDAO extends IGenericDao<Criterion, Long> {
 
     public void removeByNameAndType(Criterion criterion);
 
-    Criterion findByNameAndType(Criterion criterion);
+    List<Criterion> findByNameAndType(Criterion criterion);
+
+    Criterion findUniqueByNameAndType(Criterion criterion) throws InstanceNotFoundException;
 
     boolean existsByNameAndType(Criterion entity);
 
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/impl/CriterionDAO.java b/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/impl/CriterionDAO.java
index 0d40ba343..507233c51 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/impl/CriterionDAO.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/impl/CriterionDAO.java
@@ -1,7 +1,9 @@
 package org.navalplanner.business.resources.daos.impl;
 
-import java.util.logging.Level;
-import java.util.logging.Logger;
+import java.util.List;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.hibernate.Criteria;
 import org.hibernate.criterion.Restrictions;
 import org.navalplanner.business.common.daos.impl.GenericDaoHibernate;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
@@ -10,36 +12,58 @@ import org.navalplanner.business.resources.entities.Criterion;
 
 /**
  * DAO implementation for Criterion. <br />
+ *
  * @author Óscar González Fernández <ogonzalez@igalia.com>
+ * @author Diego Pino García <dpino@igalia.com>
  */
 public class CriterionDAO extends GenericDaoHibernate<Criterion, Long>
         implements ICriterionDAO {
 
-    public Criterion findByNameAndType(Criterion criterion) {
-        return (Criterion) getSession().createCriteria(Criterion.class).add(
-                Restrictions.eq("name", criterion.getName())).add(
-                Restrictions.eq("type", criterion.getType())).uniqueResult();
+    private static final Log log = LogFactory.getLog(CriterionDAO.class);
+
+    @Override
+    public List<Criterion> findByNameAndType(Criterion criterion) {
+        Criteria c = getSession().createCriteria(Criterion.class);
+
+        c.add(Restrictions.eq("name", criterion.getName()).ignoreCase());
+        c.add(Restrictions.eq("type", criterion.getType()).ignoreCase());
+
+        List result = (List<Criterion>) c.list();
+
+        return result;
+    }
+
+    public Criterion findUniqueByNameAndType(Criterion criterion) throws InstanceNotFoundException {
+        List<Criterion> list = findByNameAndType(criterion);
+
+        if (list.size() != 1)
+            throw new InstanceNotFoundException(criterion, Criterion.class
+                    .getName());
+
+        return list.get(0);
     }
 
     public boolean existsByNameAndType(Criterion criterion) {
-        return findByNameAndType(criterion) != null;
+        try {
+            return findUniqueByNameAndType(criterion) != null;
+        } catch (InstanceNotFoundException e) {
+            return false;
+        }
     }
 
     @Override
     public Criterion find(Criterion criterion) throws InstanceNotFoundException {
         if (criterion.getId() != null)
             return super.find(criterion.getId());
-        Criterion result = findByNameAndType(criterion);
-        if (result == null)
-            throw new InstanceNotFoundException(criterion, Criterion.class
-                    .getName());
+        Criterion result = findUniqueByNameAndType(criterion);
+
         return result;
     }
 
     @Override
     public void removeByNameAndType(Criterion criterion) {
-        Criterion reloaded = findByNameAndType(criterion);
         try {
+            Criterion reloaded = findUniqueByNameAndType(criterion);
             remove(reloaded.getId());
         } catch (InstanceNotFoundException ex) {
             throw new RuntimeException(ex);
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/Criterion.java b/navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/Criterion.java
index 3fca9d4ca..cfdb7515d 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/Criterion.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/Criterion.java
@@ -4,6 +4,7 @@ import java.util.Date;
 
 import org.apache.commons.lang.Validate;
 import org.apache.commons.lang.builder.EqualsBuilder;
+import org.apache.commons.lang.builder.ToStringBuilder;
 import org.hibernate.validator.NotEmpty;
 
 /**
@@ -93,4 +94,8 @@ public class Criterion implements ICriterion {
         return false;
     }
 
+    @Override
+    public String toString() {
+        return new ToStringBuilder(this).getStringBuffer().toString();
+    }
 }
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/resources/services/CriterionService.java b/navalplanner-business/src/main/java/org/navalplanner/business/resources/services/CriterionService.java
index 47f7fd15e..2bdb31668 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/resources/services/CriterionService.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/resources/services/CriterionService.java
@@ -6,6 +6,7 @@ import java.util.List;
 
 import org.navalplanner.business.common.OnTransaction;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
+import org.navalplanner.business.common.exceptions.ValidationException;
 import org.navalplanner.business.resources.entities.Criterion;
 import org.navalplanner.business.resources.entities.CriterionSatisfaction;
 import org.navalplanner.business.resources.entities.ICriterion;
@@ -23,7 +24,14 @@ public interface CriterionService {
 
     void remove(Criterion criterion) throws InstanceNotFoundException;
 
-    void save(Criterion entity);
+    /**
+     * Save or update criterion
+     *
+     * "name" and "type" fields must be both unique
+     *
+     * @param entity
+     */
+    void save(Criterion entity) throws ValidationException;
 
     Collection<Resource> getResourcesSatisfying(ICriterion criterion);
 
@@ -36,7 +44,7 @@ public interface CriterionService {
     Collection<CriterionSatisfaction> getSatisfactionsFor(
             ICriterionType<?> criterionType, Date begin, Date end);
 
-    void createIfNotExists(Criterion criterion);
+    void createIfNotExists(Criterion criterion) throws ValidationException;
 
     boolean exists(Criterion criterion);
 
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/resources/services/impl/CriterionServiceImpl.java b/navalplanner-business/src/main/java/org/navalplanner/business/resources/services/impl/CriterionServiceImpl.java
index 96bbde5fd..3d272cca1 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/resources/services/impl/CriterionServiceImpl.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/resources/services/impl/CriterionServiceImpl.java
@@ -5,9 +5,12 @@ import java.util.Collection;
 import java.util.Date;
 import java.util.List;
 
+import javax.transaction.RollbackException;
 import org.apache.commons.lang.Validate;
+import org.hibernate.validator.InvalidValue;
 import org.navalplanner.business.common.OnTransaction;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
+import org.navalplanner.business.common.exceptions.ValidationException;
 import org.navalplanner.business.resources.daos.ICriterionDAO;
 import org.navalplanner.business.resources.daos.impl.CriterionDAO;
 import org.navalplanner.business.resources.entities.Criterion;
@@ -57,18 +60,19 @@ public class CriterionServiceImpl implements CriterionService {
         }
     }
 
-    public void save(Criterion entity) {
-        if (criterionDAO.existsByNameAndType(entity)) {
-            /*
-             * TODO It's an unchecked exception by now. I consider this error an
-             * expected error condition, so we should send a checked exception.
-             */
-            throw new RuntimeException(
-                    "there must be only one criterion with name "
-                            + entity.getName() + " and type "
-                            + entity.getType());
-        }
+    @Transactional(rollbackFor=ValidationException.class)
+    public void save(Criterion entity) throws ValidationException {
         criterionDAO.save(entity);
+        if (criterionDAO.findByNameAndType(entity).size() > 1) {
+
+            InvalidValue[] invalidValues = {
+                new InvalidValue(entity.getName() + " already exists",
+                    Criterion.class, "name", entity.getName(), entity)
+            };
+
+            throw new ValidationException(invalidValues,
+                "Couldn't save new criterion");
+        }
     }
 
     @Override
@@ -119,7 +123,7 @@ public class CriterionServiceImpl implements CriterionService {
     }
 
     @Override
-    public void createIfNotExists(Criterion criterion) {
+    public void createIfNotExists(Criterion criterion) throws ValidationException {
         if (!exists(criterion))
             save(criterion);
     }
diff --git a/navalplanner-business/src/test/java/org/navalplanner/business/test/resources/services/CriterionServiceTest.java b/navalplanner-business/src/test/java/org/navalplanner/business/test/resources/services/CriterionServiceTest.java
index b3653d38d..014ea414b 100644
--- a/navalplanner-business/src/test/java/org/navalplanner/business/test/resources/services/CriterionServiceTest.java
+++ b/navalplanner-business/src/test/java/org/navalplanner/business/test/resources/services/CriterionServiceTest.java
@@ -10,6 +10,7 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.navalplanner.business.common.OnTransaction;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
+import org.navalplanner.business.common.exceptions.ValidationException;
 import org.navalplanner.business.resources.entities.Criterion;
 import org.navalplanner.business.resources.entities.CriterionSatisfaction;
 import org.navalplanner.business.resources.entities.CriterionWithItsType;
@@ -88,7 +89,7 @@ public class CriterionServiceTest {
                 PredefinedCriterionTypes.WORK_RELATIONSHIP).size(),
                 equalTo(initial + 1));
         criterion.setActive(false);
-        String newName = "prueba";
+        String newName = UUID.randomUUID().toString() + "random";
         criterion.setName(newName);
         criterionService.save(criterion);
         assertThat("after editing there are the same", criterionService
@@ -99,18 +100,29 @@ public class CriterionServiceTest {
         criterionService.remove(criterion);
     }
 
-    @Test(expected = Exception.class)
-    public void testUniqueNameForCriterion() {
+    @Test
+    public void testSaveCriterionTwice() throws ValidationException {
         String unique = UUID.randomUUID().toString();
         Criterion criterion = PredefinedCriterionTypes.WORK_RELATIONSHIP
                 .createCriterion(unique);
         criterionService.save(criterion);
-        criterionService.save(PredefinedCriterionTypes.WORK_RELATIONSHIP
-                .createCriterion(unique));
+        criterionService.save(criterion);
+    }
+
+    @Test(expected=ValidationException.class)
+    @NotTransactional
+    public void testCannotExistTwoDifferentCriterionsWithSameNameAndType() throws ValidationException {
+        String unique = UUID.randomUUID().toString();
+        Criterion criterion = PredefinedCriterionTypes.WORK_RELATIONSHIP
+                .createCriterion(unique);
+        criterionService.save(criterion);
+        Criterion criterion2 = PredefinedCriterionTypes.WORK_RELATIONSHIP
+                .createCriterion(unique);
+        criterionService.save(criterion2);
     }
 
     @Test
-    public void testCreateIfNotExists() {
+    public void testCreateIfNotExists() throws ValidationException {
         String unique = UUID.randomUUID().toString();
         Criterion criterion = PredefinedCriterionTypes.WORK_RELATIONSHIP
                 .createCriterion(unique);
@@ -186,7 +198,7 @@ public class CriterionServiceTest {
     }
 
     @Test
-    public void testGetSetOfResourcesSubclassSatisfyingCriterion() {
+    public void testGetSetOfResourcesSubclassSatisfyingCriterion() throws ValidationException {
         Criterion criterion = CriterionDAOTest.createValidCriterion();
         criterionService.save(criterion);
         ICriterionType<Criterion> type = createTypeThatMatches(criterion);
@@ -203,7 +215,7 @@ public class CriterionServiceTest {
     }
 
     @Test
-    public void shouldLetCreateCriterionOnData() {
+    public void shouldLetCreateCriterionOnData() throws ValidationException {
         Criterion criterion = CriterionDAOTest.createValidCriterion();
         ICriterionType<?> type = createTypeThatMatches(criterion);
         criterionService.save(criterion);
@@ -260,7 +272,7 @@ public class CriterionServiceTest {
 
     @Test
     @NotTransactional
-    public void shouldntThrowExceptionDueToTransparentProxyGotcha() {
+    public void shouldntThrowExceptionDueToTransparentProxyGotcha() throws ValidationException {
         Criterion criterion = CriterionDAOTest.createValidCriterion();
         ICriterionType<Criterion> type = createTypeThatMatches(criterion);
         criterionService.save(criterion);
@@ -274,7 +286,7 @@ public class CriterionServiceTest {
     }
 
     @Test(expected = IllegalArgumentException.class)
-    public void mustBeCorrectInterval() {
+    public void mustBeCorrectInterval() throws ValidationException {
         Criterion criterion = CriterionDAOTest.createValidCriterion();
         criterionService.save(criterion);
         criterionService.getResourcesSatisfying(criterion,
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/resources/criterion/CriterionAdminController.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/resources/criterion/CriterionAdminController.java
index 913d76aca..6ad195dd8 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/resources/criterion/CriterionAdminController.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/resources/criterion/CriterionAdminController.java
@@ -2,6 +2,8 @@ package org.navalplanner.web.resources.criterion;
 
 import java.util.List;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.navalplanner.business.common.exceptions.ValidationException;
 import org.navalplanner.business.resources.entities.Criterion;
 import org.navalplanner.business.resources.entities.ICriterionType;
@@ -31,6 +33,8 @@ import org.zkoss.zul.api.Group;
  */
 public class CriterionAdminController extends GenericForwardComposer {
 
+    private static final Log log = LogFactory.getLog(CriterionAdminController.class);
+
     private ICriterionsModel criterionsModel;
 
     private Component messagesContainer;
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/resources/criterion/CriterionsModel.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/resources/criterion/CriterionsModel.java
index 43fab7e9b..9b30bbc0a 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/resources/criterion/CriterionsModel.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/resources/criterion/CriterionsModel.java
@@ -5,6 +5,8 @@ import java.util.Collection;
 import java.util.List;
 
 import org.apache.commons.lang.Validate;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.hibernate.validator.ClassValidator;
 import org.hibernate.validator.InvalidValue;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
@@ -31,6 +33,8 @@ import org.springframework.transaction.annotation.Transactional;
 @Scope(BeanDefinition.SCOPE_PROTOTYPE)
 public class CriterionsModel implements ICriterionsModel {
 
+    private static final Log log = LogFactory.getLog(CriterionsModel.class);
+
     private ClassValidator<Criterion> criterionValidator = new ClassValidator<Criterion>(
             Criterion.class);
 
@@ -88,15 +92,20 @@ public class CriterionsModel implements ICriterionsModel {
     }
 
     @Override
-    @Transactional
     public void saveCriterion() throws ValidationException {
         InvalidValue[] invalidValues = criterionValidator
                 .getInvalidValues(criterion);
         if (invalidValues.length > 0)
             throw new ValidationException(invalidValues);
-        criterionService.save(criterion);
-        criterion = null;
-        criterionType = null;
+
+        try {
+            criterionService.save(criterion);
+        } catch (ValidationException ve) {
+            throw ve;
+        } finally {
+            criterion = null;
+            criterionType = null;
+        }
     }
 
     @Override