I have never had this problem before up until a month ago, but everytime I want to do a U Drive It mission SC just stops responding, the music stops playing but you can still hear the city sounds (the cars, etc.). I have to use the ctrl+alt+delete method to stop the game otherwise it will sit there doing nothing..Before, the only problem I had was when it came to going up slopes, it would seem to stall a little bit but now it wont even go.