I'm currently having the same problem, and I believe the hardware, and the drivers I have are up to par.
Core 2 Quad E6600
Quadro FX 1700 (Nvidia 169.61 Drivers from Autodesk link)
Windows Vista Ultimate x64
4gigs DDR2 800
limitless hard drive space (storage farm available)
I believe the rest of the hardware specifications are irrelevant.
I'm currently unable to use the manipulators on any of the faces of any object in any view, I only have an extremely LONG line that spans out in the direct the manipulator would normally be. Also I have tried the newest drivers from Nvidia (175.51 As of 5/14/08) without success.
I was able to use the manipulators before when I installed Maya and ran it for the few 2-5 times. I updated drivers because I was having a different issue which is now resolved, but this one is killing me.
Lastly the universal manipulator doesn't show up at all, under any conditions, with any type of object, under any selections. I know I installed a good copy of maya because I've tested it on multiple computers, without issues, but the computer it is required to be on is having problems. I'm at a loss, and hope that you guys might be able to shed some light on this problem.