diff --git a/libreplan-business/src/main/java/org/libreplan/business/common/daos/GenericDAOHibernate.java b/libreplan-business/src/main/java/org/libreplan/business/common/daos/GenericDAOHibernate.java
index d8b8637e6..012d30304 100644
--- a/libreplan-business/src/main/java/org/libreplan/business/common/daos/GenericDAOHibernate.java
+++ b/libreplan-business/src/main/java/org/libreplan/business/common/daos/GenericDAOHibernate.java
@@ -85,21 +85,14 @@ public class GenericDAOHibernate<E extends BaseEntity,
         return entityClass;
     }
 
-    public void save(E entity) throws ValidationException {
-        save(entity, Mode.AUTOMATIC_FLUSH);
-    }
-
     /**
      * It's necessary to save and validate later.
      *
      * Validate may retrieve the entity from DB and put it into the Session, which can eventually lead to
      * a NonUniqueObject exception. Save works here to reattach the object as well as saving.
      */
-    public void save(E entity, Mode mode) throws ValidationException {
+    public void save(E entity) throws ValidationException {
         getSession().saveOrUpdate(entity);
-        if (mode == Mode.FLUSH_BEFORE_VALIDATION) {
-            getSession().flush();
-        }
         entity.validate();
     }
 
diff --git a/libreplan-business/src/main/java/org/libreplan/business/common/daos/IGenericDAO.java b/libreplan-business/src/main/java/org/libreplan/business/common/daos/IGenericDAO.java
index 078684f1a..f3bf94747 100644
--- a/libreplan-business/src/main/java/org/libreplan/business/common/daos/IGenericDAO.java
+++ b/libreplan-business/src/main/java/org/libreplan/business/common/daos/IGenericDAO.java
@@ -42,19 +42,7 @@ public interface IGenericDAO <E, PK extends Serializable>{
 
     public Class<E> getEntityClass();
 
-    public enum Mode {
-        FLUSH_BEFORE_VALIDATION, AUTOMATIC_FLUSH;
-    }
-
     /**
-     * It saves with automatic flush
-     *
-     * @see #save(Object, Mode)
-     */
-    public void save(E entity) throws ValidationException;
-
-    /**
-     * <p>
      * It inserts the object passed as a parameter in the ORM session, planning
      * it for updating (even though it is not modified before or after the call
      * to this method) or insertion, depending if it is was detached or
@@ -63,15 +51,11 @@ public interface IGenericDAO <E, PK extends Serializable>{
      * executed (if the entity has version control enabled) with the possible
      * <code>org.springframework.dao.OptimisticLockingFailureException</code>
      * being thrown.
-     * </p>
-     * <p>
-     *
-     * </p>
      *
      * @throws ValidationException
      *             if the entity has some invalid values
      */
-    public void save(E entity, Mode mode) throws ValidationException;
+    public void save(E entity) throws ValidationException;
 
     /**
      * Unlike <code>save</code>, it does not execute validations.
diff --git a/libreplan-webapp/src/main/java/org/libreplan/web/common/ConfigurationModel.java b/libreplan-webapp/src/main/java/org/libreplan/web/common/ConfigurationModel.java
index 8f5a69405..295ad3301 100644
--- a/libreplan-webapp/src/main/java/org/libreplan/web/common/ConfigurationModel.java
+++ b/libreplan-webapp/src/main/java/org/libreplan/web/common/ConfigurationModel.java
@@ -35,7 +35,6 @@ import org.libreplan.business.calendars.daos.IBaseCalendarDAO;
 import org.libreplan.business.calendars.entities.BaseCalendar;
 import org.libreplan.business.common.daos.IConfigurationDAO;
 import org.libreplan.business.common.daos.IEntitySequenceDAO;
-import org.libreplan.business.common.daos.IGenericDAO.Mode;
 import org.libreplan.business.common.entities.Configuration;
 import org.libreplan.business.common.entities.EntityNameEnum;
 import org.libreplan.business.common.entities.EntitySequence;
@@ -49,6 +48,7 @@ import org.libreplan.web.common.concurrentdetection.OnConcurrentModification;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.context.annotation.Scope;
+import org.springframework.dao.OptimisticLockingFailureException;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
@@ -149,8 +149,13 @@ public class ConfigurationModel implements IConfigurationModel {
     @Transactional
     public void confirm() {
         checkEntitySequences();
-        configurationDAO.save(configuration, Mode.FLUSH_BEFORE_VALIDATION);
-        storeAndRemoveEntitySequences();
+        configurationDAO.save(configuration);
+        try {
+            storeAndRemoveEntitySequences();
+        } catch (IllegalStateException e) {
+            throw new OptimisticLockingFailureException(
+                    "concurrency problem in entity sequences");
+        }
     }
 
     private void checkEntitySequences() {