The x32 Windows code should be pretty well tested. If this is using the x64 code though, that's all quite new. I'll give this a try when I find some time, but can't suggest a workaround offhand. It almost sounds alignment-related, which could be tricky.
This is using the x86 (32-bit) code, so I'm not sure what could be going wrong. Is it well-tested on Windows too? Seems like something about the interaction between the fiber context/stack and SEH is not happy.
