Alt+Right Arrow takes me from video viewer to video editor. I don't think that is for Movie Maker 10. I'm pretty sure it's for the Movie Maker I'm trying to replace.
I just got home, and you're right. I'm actually running Windows Live Movie Maker, and those hotkeys don't work here either. On this version it's "J" and "L" that moves one frame at a time.
I must be running something different at work, because the arrow keys worked there. Sorry about that.