Comment 4 for bug 479031

I have the same problem, with identical backtrace in Xorg.log, but on different configuration:

Kubuntu 9.10 x86_64
ATI Radeon HD 3400 Series
Composition turned on (KWin desktop effects)

On my system, the bug occurs only in one place:

1. New email received in Kmail
2. I try to make a selection of some text in received email, X crashes completely, even Ctrl-Alt-Fn is not functional.

Note: in 99% of cases, email where crash happened is lost, so take care if you are testing.

It does not happens always, but enough frequently that it is annoying. I even try to never start selection on a newly received email in kmail.