Looks like I have a problem that has already been debated but non of the solutions provided did not work for me, so I'm asking this question again in hpes that someone can help me.
I'm running 12.04 64 bit version on Lenovo E520 with AMD Radeon HD 6600M and Intel HD graphic. I was using catalyst 12.6 driver downloaded and installed from http://support.amd.com/us/gpudownload/windows/previous/12/Pages/radeon_linux.aspx?os=Linux%20x86&rev=12.6.
However my system unexpectedly crashed with the "your system is running in low graphic card error". Since than I've removed the old ATI driver and installed the 12.8 version following their instructions with no problems, however the error still remains. If I use open source drivers I can use Ubuntu, but it slow to the point I can't even use gnome 3.
Previous solutions described do not work for me: Your system is running in low-graphics mode with an ATI Radeon 3200 Graphics card