Index: trunk/autoquest-core-usability/src/main/java/de/ugoe/cs/autoquest/usability/CheckBoxMultipleSelectionRule.java
===================================================================
--- trunk/autoquest-core-usability/src/main/java/de/ugoe/cs/autoquest/usability/CheckBoxMultipleSelectionRule.java	(revision 2042)
+++ trunk/autoquest-core-usability/src/main/java/de/ugoe/cs/autoquest/usability/CheckBoxMultipleSelectionRule.java	(revision 2135)
@@ -217,8 +217,8 @@
          */
         private void addValueChange(IEventTaskInstance instance) {
-            IGUIElement target = (IGUIElement) instance.getEvent().getTarget();
+            IEventTarget target = instance.getEvent().getTarget();
             
             if (target instanceof ICheckBox) {
-                checkBoxes.add(target);
+                checkBoxes.add((ICheckBox) target);
             }
         }
Index: trunk/autoquest-core-usability/src/main/java/de/ugoe/cs/autoquest/usability/UnusedGUIElementsRule.java
===================================================================
--- trunk/autoquest-core-usability/src/main/java/de/ugoe/cs/autoquest/usability/UnusedGUIElementsRule.java	(revision 2042)
+++ trunk/autoquest-core-usability/src/main/java/de/ugoe/cs/autoquest/usability/UnusedGUIElementsRule.java	(revision 2135)
@@ -165,4 +165,8 @@
         }
         
+        if (result.size() <= 0) {
+            return result;
+        }
+
         // the problem is, that using the GUI model does not allow to find all in a specific view
         // as the GUI model may return a merged element instead. But anyway, we can add those, which