Correct me if I'm wrong, But I believe some one mentioned using the Catalyst 3.2 or even the 2.2 drivers to get the game working.
For SFC3, Do you have the Beta Patch? I'd try that first, as your system is more then enough to run SFC3, Not sure about EF2 though, as I don't have that game yet.
You can find a link to the patch in the announcement section of the forums, Or the Various fan sites, such as SFC3.net , SFC universe, ToastO's site, Or of course XenoCorp. also capt. Castrin has a site also.
Too many to recall at one time actually.
Stephen