Buttons stopped responding to clicks

FROM : Tim Hewett
DATE : Mon Nov 05 03:03:14 2007

I have a problem where the buttons and other responders in my app have 
stopped responding in a particular subview under Leopard. Other views 
are unaffected.

The app works fine under Tiger and Panther, but when running the Tiger-
built executable under Leopard the buttons etc. do not respond and 
instead the textured window is just dragged as if you are clicking on 
the background.

Building and running the app under Leopard makes no difference.

The affected view is one of three contained in a NSSplitView.

Anyone else had this and found the cause/cure?