wow, I've been looking all around the net for a solution, I have the same problem, it's driving me mad... I have Maya 2008 and I installed windows XP 32bit with service pack 2. It seems like Maya wants to automatically select the closest rotation angle according to the viewport... Also, if I want to deselect the manipulator by clicking in an empty space, I have to go very far from the manipulator when I have rotation tool selected.... I'll try uninstalling and reinstalling Maya, but I fear it won't help....