Index: /trunk/autoquest-core-usability-evaluation/src/main/java/de/ugoe/cs/autoquest/usability/tasktree/FilterResult.java
===================================================================
--- /trunk/autoquest-core-usability-evaluation/src/main/java/de/ugoe/cs/autoquest/usability/tasktree/FilterResult.java	(revision 1161)
+++ /trunk/autoquest-core-usability-evaluation/src/main/java/de/ugoe/cs/autoquest/usability/tasktree/FilterResult.java	(revision 1162)
@@ -45,5 +45,5 @@
     @SuppressWarnings("unchecked")
     public void addTask(ITask task) {
-        if (filterPredicate.apply(task)) {
+        if (filterPredicate.apply(task) && !filteredTasks.contains(task)) {
             filteredTasks.add(task);
         }