diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/calendars/entities/CalendarExceptionType.java b/navalplanner-business/src/main/java/org/navalplanner/business/calendars/entities/CalendarExceptionType.java
index dd0a143a1..1fd468735 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/calendars/entities/CalendarExceptionType.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/calendars/entities/CalendarExceptionType.java
@@ -28,6 +28,7 @@ import java.util.EnumMap;
 import org.apache.commons.lang.BooleanUtils;
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang.Validate;
+import org.hibernate.NonUniqueResultException;
 import org.hibernate.validator.AssertTrue;
 import org.hibernate.validator.NotNull;
 import org.navalplanner.business.calendars.daos.ICalendarExceptionTypeDAO;
@@ -36,6 +37,7 @@ import org.navalplanner.business.common.Registry;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
 import org.navalplanner.business.workingday.EffortDuration;
 import org.navalplanner.business.workingday.EffortDuration.Granularity;
+import org.springframework.orm.hibernate3.HibernateOptimisticLockingFailureException;
 
 /**
  * Type of an exception day.
@@ -172,7 +174,12 @@ public class CalendarExceptionType extends IntegrationEntity {
                 return calendarExceptionType.getId().equals(getId());
             } catch (InstanceNotFoundException e) {
                 return true;
+            } catch (NonUniqueResultException e) {
+                return false;
+            } catch (HibernateOptimisticLockingFailureException e) {
+                return true;
             }
+
         }
     }
 
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/exceptionDays/CalendarExceptionTypeModel.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/exceptionDays/CalendarExceptionTypeModel.java
index b57cfcdde..ac5eb2256 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/exceptionDays/CalendarExceptionTypeModel.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/exceptionDays/CalendarExceptionTypeModel.java
@@ -48,7 +48,7 @@ import org.zkoss.util.InvalidValueException;
  */
 @Service
 @Scope(BeanDefinition.SCOPE_PROTOTYPE)
-@OnConcurrentModification(goToPage = "/exceptionDays/exceptionDays.zul")
+@OnConcurrentModification(goToPage = "/excetiondays/exceptionDays.zul")
 public class CalendarExceptionTypeModel extends IntegrationEntityModel
         implements ICalendarExceptionTypeModel {