Hi to all!!! I'm new here! I'm italian so excuse me for my poor english I 'have the same problem. But I find the real Solution!! It 's not a graphic drivers problem but a bug of maya Seem like a layout problem becouse if you change the camera to top or side or front the manipulator is missing like persp. So I resolve it :attn: Go to the bug panel and and set it to hypershade then press "w" button some times... then retourn to persp and now you have your manipulator in your persp panel!...or better... in your bug layout panel... have a nice day!!!