My guess: time for a new mouse.
Today I have had a real problem keeping my usb mouse connected to my laptop, working. It will be fine for 30 mins or so, and then stop moving. Fortunately I have a touchpad, but still I much prefer the mouse. It is close to 10 years old.
I have uninstalled the driver via the device manager (running XP SP3), rebooted, then let WIndows install its own driver. This didn't work, so I uninstalled, rebooted, and then told windows to find the drivers I d/l from the HP site. Same thing.
Any suggestions? I can always buy a new mouse, but I'd like to troubleshoot, esp. b/c this has never occurred before.