P.S. The above script and failure is running on winxp sp3.  Also, if 
you comment out the two os.system() calls, it works just fine.  They 
seem like they should be unrelated to the logging though.  You'll also 
see some errors about access to the blah.txt file which makes sense 
since multiple threads are hitting that file at the same time.  I don't 
know if this is about using os.system() itself from multiple threads 
while logging or if it's about having an error condition during the 
os.system() call on top of that.  Anyway, let me know what you think or 
if I've done something wrong, let me know how to fix it and that might 
be good documentation for others running into this problem.  Thanks.