If you tried reinstalling drivers, are running the games as administrator and have vsync off, your best bet is to set everything to low in the game and see what your frame rate does.
If it's still around 30fps even with lowest graphics settings, something is seriously wrong on your end ;-)
I played the Just Cause 2 demo on a laptop with a mobility FireGL V5700 and got myself some 20fps..so a GTX470 shouldn't be giving you 30fps only.
If you do get good frame rates on lowest settings, you have to start turning up features one-by-one in the game, checking each time what sort of performance hit you get.
Ideally, there will be a point where you switch something on and your fps start dropping again.
In the worst case, it might take dozens of combinations and different driver settings :-/
I also recommend you go and check out the game forums:
Especially with console ports, there can often be some problem in the game's coding that can be resolved by workarounds (driver downgrade, obscure combinations that have to be avoided, etc)
Alex
PS: At the fps issue:
24 frames per second are enough to convince the brain that one is seeing motion - however, that only works if something was recorded and the recording medium was exposed for 1/24th of a second...
Because that means that each of the 24 frames will have "motion blur" (go through a movie frame by frame)
If you however take 24 frames from a pc game, it will be 24 "perfect" images of the moment that each frame was calculated at.
Therefore there is no motion blur (the "motion blur" in games is something completely different again and has little to do with real motion blur when filming a movie*)
That means that the brain needs a lot more images per second to be fooled into seeing fluid motion, otherwise the changes between two frames are too extreme.
Then the monitor enters the equation: Most LCD's refresh 60 times a second, some 80times, some even 120times.
Now, what Vsync does is basically "wait" for the LCD to refresh before rendering another frame (that's not really correct, but gets the idea across)
However, that still shouldn't put you at 30fps.
*real motion blur in games actually requires the engine to calculate several "perfect" frames and then compile them together into one "blurred" frame