--- a/src/common/f-variable-tracer.h	Tue Oct 03 12:21:13 2006 +0200
+++ b/src/common/f-variable-tracer.h	Fri Oct 06 13:37:25 2006 +0200
@@ -44,7 +44,7 @@
     }
 protected:
     void notify (double oldVal, double newVal) {
-        if (oldVal != newVal && !m_callback.isNull ()) {
+        if (oldVal != newVal && !m_callback.IsNull ()) {
             m_callback (oldVal, newVal);
         }
     }