Comment 21 for bug 564617

Regarding the kernel used by ubuntu, the changelog is there : http://changelogs.ubuntu.com/changelogs/pool/main/l/linux/linux_2.6.32-21.32/changelog

There has been a few changes that consist in disabling acceleration for specific cards. See for example https://bugs.launchpad.net/ubuntu/+source/linux/+bug/544088
Well, disabling acceleration is a workaround in my opinion, not a real fix...