It's a bug, and one that's probably trivial to fix if we can pin down the combination of CPU and libraries etc that provoke it.

Are you using the latest unstable tree? Does my test program still indicate a problem for you? If so, please post the output of /proc/cpuinfo, and information about your distribution and libraries.

Like the only other pending bug (the network panic bug) it seems only to effect a minority of users, and we can't seem to reproduce it locally. Until we get more information I'm afraid there's not a lot we can do beyond simply reviewing the code.

Thanks, Ian