diff -r 08dd52950883 -r 41a4abecb600 samples/deadlock/test/org/apidesign/javamonitorflaws/MultiplyCache.java
--- a/samples/deadlock/test/org/apidesign/javamonitorflaws/MultiplyCache.java	Tue Feb 10 18:36:21 2009 +0100
+++ b/samples/deadlock/test/org/apidesign/javamonitorflaws/MultiplyCache.java	Wed Feb 11 07:12:41 2009 +0100
@@ -28,7 +28,7 @@
         }
         pcs.addPropertyChangeListener(listener);
     }
-    public void removePropertyChangeListener(PropertyChangeListener listener) {
+    public synchronized void removePropertyChangeListener(PropertyChangeListener listener) {
         if (pcs != null) {
             pcs.removePropertyChangeListener(listener);
         }