window-null-event-handler semiphore

[paul_hasse@NSDGATE3.nsd.fmc.com (paul hasse)]

I have installed an :after method on the window-null-event-handler.  I have 
noticed that this handler seems to be called at virtually any time.  Is this 
true?  What I need to be able to do is lock out this event handler while I do 
some processing, do the processing and then restart the event handler.  What I 
really need is a semiphore.  Any suggestions?