https://bugs.freedesktop.org/show_bug.cgi?id=44800
--- Comment #10 from Alexandre Demers alexandre.f.demers@gmail.com 2012-08-10 20:07:23 UTC --- May or may not be related, but I've seen similar corruption with CAYMAN related to bug 45018 from time to time. But about comment 3, I was tempted to point at bug 42373.
Marko, if you are willing to try patches proposed in both mentionned bugs to see if it helps in any way, that could be interesting.