3fps! That's a bit odd.
I'm running Ultra High settings (125%) with only AA turned off and it's fine on a C2Q 9550 with an ATI 5850 @ 1900x1200. AA on had a significant performance hit when I upgraded the monitor earlier in the month. Ran fine with AA enabled at 1680x1050, but 1900x1200 was too much.
Thanks good info. I am certain there is an underlying issue and that I should be able to run it! Just can't work out what's going wrong.