Aerbabe
I have mouse problems as well, on my laptop when the separate (cordless) mouse is plugged in. (Its a logitech cordless optical type). In my case when I'm typing the cursor sometimes jumps to another part of the screen which is pretty annoying, especially when I'm slow, as it is.
Is your computer a desktop type, or a laptop? Wonder if its worth running defrag' - it just might help...
Fujiflyer