Mousedown on selected highlighted text => Windows crash

[depstein at att.net]

I have encountered a situation that crashes Metacard running in Windows XP 
almost always but not invariably.  Here's the pattern:

1.  a chunk of text in a field has a backColor (like a yellow highlight)
2.  I select some of that backColored chunk using the mouse
3.  I press down the mouse on top of the selected, backColored chunk.

On the Mac, this has never caused a problem.  The mouseDown in step 3 
results in the little rectangular cursor being displayed, indicating the 
program is ready to "drag and drop" my selection whenever I release the 
mouse.  Sometimes this works fine in Windows too.  But most of the time the 
Windows result is that no rectangular cursor appears, and the program crashes immediately:

 "mc.exe has generated errors and will be closed by Windows.  
You will need to restart the program.  An error log is being created."  

And Metacard does indeed quit.

I tried this with the message watcher on, and the crash seems to be triggered at "dragStart."  I 
tried it with a breakpoint in my dragStart handler, and the crash happened at the end of that 
handler, where I "pass dragStart."  I tried commenting out my dragStart handler.  This did not 
prevent the crash.

The fact that this does not always happen (and never happens on the Mac) made me think the 
variation might be related to available memory; but I have not found a pattern.  On the assumption 
that something in my scripts is the culprit, I've tried to reproduce this bug by opening some stacks 
with no scripts, just a lot of text and some yellow highlighting.  I have not yet reproduced the bug 
under those laboratory conditions. 

Has anyone experienced something similar?  Does anyone know how to go about 
diagnosing such a problem?

Many thanks.

David Epstein