You need to get the Omega drivers for your ATI card. They are the only things I use now. They are based on the latest ATI Catalyst drivers but they are tweaked, safely.
http://www.omegadrivers.netI just got through downloading the latest Omega's for my 9800 along with upgrading DX to 9.0c. What a difference.
With the Omega's you get a new Control Panel so you have to remove ATI's Control Panel first. The Omega's come with a simple "Self Install" that completely overwrite the old drivers. (Done several times by me and never a problem yet.)
The Great News is, with this latest set you get a the new ATI Tool with which you can safely overclock your card. It will find your Max Core and Max Memory, SAFELY.
I ran it on my 9800 to find Max's on both Core and Memory, then set it back just a tad. Picked up several fps in FS2k4 at my test field.

Systemax Sabre Ultimate gaming rig.
I got all the goodies and all the power I need to run anything thrown at me for the next two months!