maybe you want to try this to see if it improves the situation: Hotfix to improve Dirt 2 performance.
• http://support.amd.c...rt2-performance.aspx
-lanux128
it would be even more crazy if that patch helped here
also its a hotfix for some 2009 drivers
and: "This driver is provided as-is and is not supported by AMD. It has not completed full AMD testing, and is only recommended for users experiencing the particular issue described above."
and it was removed from amd servers
and description says that its for ATI CrossFireX problems
I don't think it is a good idea to install this thing