+----------------------------------+
+ +
+ +
+ +
+----------------------------------+
+ B1 B2 B3 B4 +
+----------------------------------+

If buttons B1 to B4 are defined as XmPushButtons the activateCallback is NEVER called by clicking the mouse. If I change them to XmIconButtons they work perfectly. Even more confusing is if I add an armCallback to call the same method as the activateCallback it will work for XmPushButton. The spacebar will also trigger the activateCallback for XmPushButton.
The GUI design was orginally created using bx5 (Motif1.x) and has been re saved with bx6 (Motif2.x) versions.
Other GUI's converted by the same procedure appear to have correctly working activateCallbacks.

Any ideas?