running XP Pro SP3 with all the patches - well all the ones that apply to
me...
in the last week - my cursor "giggles" and when the mouse is left alone -
the cursor slowly drifts down the page.

The mouse is a dell ball mouse (yes I cleaned it) and it also happens on
optical mouse too.

I've rebooted - changed usb ports - changed mice -

Anybody got an idea?