Can anyone point me at a test that failed in this case?  A quick look
over winsig.c shows no asserts.  I didn't compare the vs2005 crt source
though, so its highly likely I just missed it...

On the broader point, it could be argued that if it is the apps
responsibility to re-enable assertions, it is also the apps
responsibility to disable them in the first place.  If other libraries
on the system attempted the same as Python, it would obviously be
undefined if Python's attempt had any actual affect - the last called
would win.  As we found with the old locale() issues, we really can't
rely on Python setting a global shared state to keep things nice.  From
a pragmatic POV, if we know the MS crt asserts on certain constants
signal numbers, can't we just avoid passing those numbers?