Index: /trunk/autoquest-core-tasktrees/src/main/java/de/ugoe/cs/autoquest/tasktrees/treeimpl/TaskTreeNode.java
===================================================================
--- /trunk/autoquest-core-tasktrees/src/main/java/de/ugoe/cs/autoquest/tasktrees/treeimpl/TaskTreeNode.java	(revision 1073)
+++ /trunk/autoquest-core-tasktrees/src/main/java/de/ugoe/cs/autoquest/tasktrees/treeimpl/TaskTreeNode.java	(revision 1074)
@@ -196,5 +196,5 @@
      */
     @Override
-    public ITaskTreeNode clone() {
+    public synchronized ITaskTreeNode clone() {
         TaskTreeNode clone = null;
         try {