Need For Speed hot pursuit on oxbow 360

Hi trying to get some help with playing this game here? Every time I go to play mine on xbox 360 for some reason my police car wont go in reverse or back up when im near a wall or near something else! I know its not the controller because I see the reverse lights lighting up like the car is gonna back up but it wont move at all! and then I loose after everyone keeps crashing into me! anyone???