I am sorry to tell you that this most likely will not be the problem . the reason I am saying this , is that I am running the game on a Win7 x64 , all current drivers non virtualized via native Bootcamp enviroment @ a iMac 27' i7 2,8 GHz , 16GB RAM , ATi 4850 The machine has no performance issues at all , because I am running COD MW2 , NFS Shift , Wolfenstein 2 and so on without any problems at all ! Same problems occured even when I still used a PC for gameing beside my older iMac ( used to be a C2Q @ 4x2,8GHz , XFX GF 8800GTX , 4GB RAM , XP-SP2 ) BTT - the same seems to be near the police station ( rear parking lot of PD , turn right and head down to the 4 lane road ) , where cars are turning either away or into the 4lane main road and then they block the intersection ( or don't leave the intersection and seem to be static in front of a traffic light - this should not be , because the vehicle turns to the right and should only see the back of the traffic light ) mainly the problems occur because of vehicles coming from the rear section of the PD - some cars will receive and accept orders by officers or directional lights but some are not ( usually vehicles which are coming from the rear part PD section or actually the road parallel to the PD parking lot ) ....... blocking the lane by officer will not solve the problem - the vehicles will not turn around ...... as soon you move the officer away or redirect ( or block ) traffic on the 4 lane road then the vehicles from the side street will just drive on but will not follow any officers commands ! so the situation will look like this .................v ..................| ................. | - - - - - - - < ..................\ - - - - - - - < > - - - - - - - - - - - - - - - - > - - - - - - - - - - - - - - - - - each dash or line stands for one vehicle , dots are placeholders only ( so they are meaningless but otherwise the format will change the lineup ) , arrows show driving direction