Comment 2 for bug 283305

Hmm, I'd like to forward this issue upstream, but first it must be retested on latest Jaunty to make sure the issue still happens there with the latest code. ISO images are available at http://cdimages.ubuntu.com/releases/jaunty/. If you can reproduce it in the LiveCD environment, you shouldn't need to modify your installed system. Also please attach a fresh Xorg.0.log from this testing.

There have been a number of improvements to R600 card support in the 6.11.0 -ati driver, so possibly this bug is gone. Please let us know once you've had a chance to test it.