What to capture to debug GUI app's slow response to mouse message s?

[Steve Stone]

I upgraded a GUI app and it now has extremely slow response (30 seconds) to
mouse clicks in its TreeView Explorer window (running under KDE).  Their
tech support person believes it is how I have Cygwin configured (although
they are unable to configure theirs to run like how I do).  The App does NOT
run slow on the Linux workstation itself, only when run from under
Cygwin/XFree86 and only when Cygwin is NOT launched as "multiwindow".  (When
I launch as multiwindow with no KDE, the app instead loses all keystroke
navigation in its TreeView!)

What tools exist that a non-X-Windows-literate person can run to capture the
messages to determine it this is a Windows NT issue (SP 6), Linux issue
(2.4.18-10, RedHat), a Cygwin issue (current) or even a KDE issue?

Thank you!

Steve Stone 503.672.5771