Bluetooth Mouse problem

Alright, so I'm about ready to throw my mouse through the wall.

Last November I bought a unibody MacBook Pro. I've been using a PowerBook G4 at work. I had a Targus Bluetooth Mouse that I was using on my work computer, and had no problems whatsoever. I went back to a corded mouse on that computer and moved the bluetooth to my new MBP.

But I have a problem. Occassionally, the mouse will become jumpy. It's not terrible, but it's annoying. I do layout and photoshop work, so it can REALLY make things difficult when it happens.

I thought maybe it was the mouse, so today I went and spent $70 on a bluetooth Apple Mighty Mouse. Mistake. It's 10 times worse. It's CONSTANTLY jumping around. As I move the cursor, it will suddenly jump like two to three inches in a random direction. it's almost impossible to position where I want it. I really would prefer the mighty mouse, but don't want to use up a USB port for a mouse.

Anyone else having this problem? Going to try the Mighty Mouse with my PowerBook at work tomorrow and see if it does it there too, but I doubt it will.