Comment 27 for bug 490228

The associated branch should have a fix for this. It certainly is a rare condition that is pretty hard to trigger. But I'm pretty sure I sorted out the logic of why it was happening.

Unfortunately, it is hard enough to trigger that I don't have a way to just say "run this" and it passes before, and fails after the fix. But regardless, I'm uploading a patch version of the .pyd file (built with mingw, maybe Alexander can do a VS2003 build?)