diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/advance/entities/AdvanceAssignment.java b/navalplanner-business/src/main/java/org/navalplanner/business/advance/entities/AdvanceAssignment.java
index cf2a3e219..37fc13bbc 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/advance/entities/AdvanceAssignment.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/advance/entities/AdvanceAssignment.java
@@ -77,26 +77,19 @@ public abstract class AdvanceAssignment extends BaseEntity {
         return this.advanceType;
     }
 
-    public void changeAdvanceTypeInParents(AdvanceType oldType,
+    public void changeAdvanceTypeInParents(final AdvanceType oldType,
             AdvanceType newType, AdvanceAssignment advance) {
         if (getOrderElement() != null) {
             OrderLineGroup parent = getOrderElement().getParent();
-            while (parent != null) {
-
+            if (parent != null) {
                 IndirectAdvanceAssignment oldIndirect = parent
                         .getIndirectAdvanceAssignment(oldType);
                 if (oldIndirect != null) {
                     parent.removeIndirectAdvanceAssignment(oldType);
-                }
-
-                if (!parent
-                        .existsIndirectAdvanceAssignmentWithTheSameType(newType)) {
                     IndirectAdvanceAssignment newIndirect = advance
                             .createIndirectAdvanceFor(parent);
                     parent.addIndirectAdvanceAssignment(newIndirect);
                 }
-
-                parent = parent.getParent();
             }
         }
     }
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/OrderElement.java b/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/OrderElement.java
index 2522ac461..3c76b424e 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/OrderElement.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/OrderElement.java
@@ -697,15 +697,13 @@ public abstract class OrderElement extends IntegrationEntity implements
             OrderElement orderElement,
             DirectAdvanceAssignment newAdvanceAssignment)
             throws DuplicateAdvanceAssignmentForOrderElementException {
-        for (DirectAdvanceAssignment directAdvanceAssignment : orderElement
-                .getDirectAdvanceAssignments()) {
-            if (AdvanceType.equivalentInDB(directAdvanceAssignment
-                    .getAdvanceType(), newAdvanceAssignment.getAdvanceType())) {
+        if (orderElement
+                .existsDirectAdvanceAssignmentWithTheSameType(newAdvanceAssignment
+                        .getAdvanceType())) {
                 throw new DuplicateAdvanceAssignmentForOrderElementException(
                         _("Duplicate Progress Assignment For Task"),
                         this,
                         OrderElement.class);
-            }
         }
         if (!orderElement.getChildren().isEmpty()) {
             for (OrderElement child : orderElement.getChildren()) {
@@ -715,6 +713,16 @@ public abstract class OrderElement extends IntegrationEntity implements
         }
     }
 
+    public boolean existsDirectAdvanceAssignmentWithTheSameType(AdvanceType type) {
+        for (DirectAdvanceAssignment directAdvanceAssignment : directAdvanceAssignments) {
+            if (AdvanceType.equivalentInDB(directAdvanceAssignment
+                    .getAdvanceType(), type)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     public BigDecimal getAdvancePercentage() {
         if ((dirtyLastAdvanceMeasurementForSpreading == null)
                 || dirtyLastAdvanceMeasurementForSpreading) {
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/OrderLineGroup.java b/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/OrderLineGroup.java
index 5cd7bf101..f8ac8650d 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/OrderLineGroup.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/OrderLineGroup.java
@@ -824,8 +824,10 @@ public class OrderLineGroup extends OrderElement implements
 
     public void addIndirectAdvanceAssignment(
             IndirectAdvanceAssignment indirectAdvanceAssignment) {
-        if (!existsIndirectAdvanceAssignmentWithTheSameType(indirectAdvanceAssignment
-                .getAdvanceType())) {
+        if ((!existsIndirectAdvanceAssignmentWithTheSameType(indirectAdvanceAssignment
+                .getAdvanceType()))
+                && (!existsDirectAdvanceAssignmentWithTheSameType(indirectAdvanceAssignment
+                        .getAdvanceType()))) {
             indirectAdvanceAssignments.add(indirectAdvanceAssignment);
         }
         if (parent != null) {
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/orders/ManageOrderElementAdvancesModel.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/orders/ManageOrderElementAdvancesModel.java
index 9da039905..10b119151 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/orders/ManageOrderElementAdvancesModel.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/orders/ManageOrderElementAdvancesModel.java
@@ -362,6 +362,7 @@ public class ManageOrderElementAdvancesModel implements
 
     @Override
     public void removeLineAdvanceAssignment(AdvanceAssignment advance) {
+        advance.setOrderElement(null);
         this.listAdvanceAssignments.remove(advance);
         orderElement.removeAdvanceAssignment(advance);
         this.advanceAssignment = null;
@@ -685,21 +686,24 @@ public class ManageOrderElementAdvancesModel implements
             } else {
                 directAdvanceAssignment = calculateFakeDirectAdvanceAssignment((IndirectAdvanceAssignment) each);
             }
-            String title = getInfoAdvanceAssignment(directAdvanceAssignment);
-            SortedSet<AdvanceMeasurement> listAdvanceMeasurements = directAdvanceAssignment
-                    .getAdvanceMeasurements();
-            if (listAdvanceMeasurements.size() > 1) {
-                for (AdvanceMeasurement advanceMeasurement : listAdvanceMeasurements) {
-                    BigDecimal value = advanceMeasurement.getValue();
-                    if ((selectedAdvances.size() > 1) && (value != null)) {
-                        BigDecimal maxValue = directAdvanceAssignment
-                                .getMaxValue();
-                        value = value.divide(maxValue, RoundingMode.DOWN);
-                    }
-                    LocalDate date = advanceMeasurement.getDate();
-                    if ((value != null) && (date != null)) {
-                        xymodel.addValue(title, Long.valueOf(date
-                                .toDateTimeAtStartOfDay().getMillis()), value);
+            if (directAdvanceAssignment != null) {
+                String title = getInfoAdvanceAssignment(directAdvanceAssignment);
+                SortedSet<AdvanceMeasurement> listAdvanceMeasurements = directAdvanceAssignment
+                        .getAdvanceMeasurements();
+                if (listAdvanceMeasurements.size() > 1) {
+                    for (AdvanceMeasurement advanceMeasurement : listAdvanceMeasurements) {
+                        BigDecimal value = advanceMeasurement.getValue();
+                        if ((selectedAdvances.size() > 1) && (value != null)) {
+                            BigDecimal maxValue = directAdvanceAssignment
+                                    .getMaxValue();
+                            value = value.divide(maxValue, RoundingMode.DOWN);
+                        }
+                        LocalDate date = advanceMeasurement.getDate();
+                        if ((value != null) && (date != null)) {
+                            xymodel.addValue(title, Long.valueOf(date
+                                    .toDateTimeAtStartOfDay().getMillis()),
+                                    value);
+                        }
                     }
                 }
             }