wm_mousemove life of it's own

I have to monitor activity in an app to shut it down when a certain amount
of time occurs (hipaa requirement).  I have a applicationevents component
and I monitor the messages for mouse and keyboard.  Works well except every
30 seconds or so I get a wm_mousemove message.  There is no movement because
the point values stay the same and nobody physically moves the mouse.   The
same happens, but not nearly as often, on the wm_ncmousemove.

Has anybody ran in to this before?  It just ain't right!

Russ