Has this happened to anyone else? My curser moves in a straight line without me even moving it. It's always in a steady straight line. I have no idea what causes this. I'm just curious.

Remove the ball and clean it with a cuetip and a small screwdriver if its an optical make sure all the sufraces and the lens are free from dust.

Ok, I'll do that later. Just dust ay...I thought it was something much more complicated than that.

I know what you mean Chris, my mouse has done the same thing on several occations, clean or not.