The interesting detail you don't tell: what is it in "close it down". A program, or just the Task Manager window itself? Both is weird, but the last is still weirder. Assuming the last, what happens if you minimize it?
A few other questions:
- Did you try another mouse already?
- Did you do a thorough check for malware?
- Does it also happen in Safe Mode?
My mouse is bringing up everything it moves over i have tried everything from uninstalling my drivers and reinstalling them.. It won't stop.. The wierd thing is..when i bring up windows task manager and then close it down again the problem is gone.. until i reboot. by the way i have windows xp home edition.