I'm running a 5200 w 256 and BF2 runs great (I can't run it higher than Low for most settings, but it works @1024x768 with no glitches or shutters) I've ran into a bit of lag but only when there were 64 peeps in the server and two of use were playing on it over my cable connection (hay we like to see the guy I'm screaming @)
There was an issue with ATI cards and the new drivers...you had to have the ones that were like 2 or 3 point releases old to get it to work right....EA and ATI were working on it though, Check EA or ATI Forums for more details (I didn't pay that much attention to it cause I's running a Nvidia card)
Crazybillybob