The only workaround I know is restarting X
Thanks for reporting this. I managed to reproduce the problem and filed a bug.
so I think they're working on this issue...
I have not seen any version that fixes this bug, although there were more than two new prereleases since this message. I havn't tried the beta driver yet, but I don't expect the bug to be fixed there yet.
You'll probably have to wait till it is fixed in a future release (or prerelease or beta release). I will report it in this thread when I recognize it to be fixed.