ever since optical mice came along, i have stopped using mousepads and just use my desk surface (wood Galant desk from Ikea) - but i also have noticed my mouse randomly will skip across the whole screen, etc.. a few times a day. i am not sure if it is my mouse itself or the lack of a pad.
do you use a mousepad?
Yep. Mostly because I need the wrist support, but also because my desks provide a horrible surface for both optical and "standard" mouses.