Recently upgraded my onboard Nvidea graphics chip with an ATI Radeon Sapphire X800XL PCIe graphics card. Ever since I am unable to run Stellarium. I get the error "This system does not support OpenGL". The only thing that has changed since I last run Stellarium (other than the weekly updates) is the new card. I have tried other fixes like this one to no avail. I have also tried to re-install the ATI plugin and Catalyst drivers in Software Center with no change. I remember once finding the list of Nvidea drivers available and being able to switch between them, where is that box again?
Found the answer on Ubuntuforums.org
It looks like my new ATI drivers were conflicting with the old Nvidea ones that required the boot first, like this:
After completing the Nvidea purge and ATI re-install all works well :)