Lost Tool Manipulators

I've been using Maya for almost a semester and a half and on a couple occasions I've lost the use of my rotate and scale manipulators in top, front, and side panel views. How do I get those working again?

delete your prefs

C:\Documents and Settings\your username\My Documents\maya\8.0\prefs

thank you

NP I hate to resort to that but I have no idea what you turned off so .. whenever maya starts acting weird I delete those prefs.