Mouse Problem

I'm at my wits' end trying to solve this. About 2 weeks ago, my mouse suddenly decided it wanted to start double clicking on its own every 5 or so clicks. Thinking it was just worn out, I got a new one - with the same results.

Running Windows XPSP2. Using generic USB optical mouse.

Tried:
- Replacing mouse. Thrice.
- Switching USB ports. Nada.
- Using same mouse on another computer. Works perfectly.
- Virus and Malware scans.
- Folder options -> Double-click to open an item.
- Reinstalling drivers.

 

here's a link to microsoft's support page for this issue.
http://support.microsoft.com/kb/266738

One thing you haven't tried is using it in safe mode. Is this happening in all programs or just certain ones?