I am going to go ou on a limb and say that this is another great Console port to PC brought to you by the Geniuses of Ubisoft, hence, the why it won't work with the newest cards out there... you gotta love DX9
I am sure that you have downloaded any of the new title updates? By now there should be at leat 1 patch or revision. Knowing UBI, you will be better off not patching from game but downloading it and then installing the patch.
Perhaps it would be better if you don't run on Beta Drivers and roll back to the previous one? How about Audio drivers? have you also updated those?
Going to the UBI forums for FC3 might yield other options... I am sure there will be plenty of responses there as well.
Good Luck.