The mouse is a Logitech Laser Mouse (says model BZ105A on the bottom) and it's on a 3M precision mousing surface, both are probably two years old. The 3M surface is more smooth in the center, but still has texture. I use a fresh install of XP32. I need precision as I work in photoshop a lot.
Any ideas what's up? Do I need a new mousing surface, or a new mouse?
Edit - a reboot didn't help, but giving the sensor a good blow and a bit of a rub has helped a bit.