Please try daily mainline-ppa https://wiki.ubuntu.com/KernelTeam/MainlineBuilds and you will need a special firmware http://xorg.freedesktop.org/wiki/radeonBuildHowTo#TroubleshootingExtraFirmwareforR600.2BAC8-R700
This sounds like null pointer deference in init failure path that was fixed in 2.6.33-rc7 or rc8. Also firmware loading problem might be fixed in newer kernel.
Please try daily mainline-ppa https:/ /wiki.ubuntu. com/KernelTeam/ MainlineBuilds and you will need a special firmware http:// xorg.freedeskto p.org/wiki/ radeonBuildHowT o#Troubleshooti ngExtraFirmware forR600. 2BAC8-R700
This sounds like null pointer deference in init failure path that was fixed in 2.6.33-rc7 or rc8. Also firmware loading problem might be fixed in newer kernel.