I recently found out why my mouse was acting weird. It was a virus called bad usb. Hitman pro alert blocked it. I thought I was going crazy. I wanted to share this with you all.
Use a PS/2 mouse, problem solved
(no, seriously, it actually solves the problem).
I'm actually surprised that Hitman Pro caught it, still a bit skeptical actually, BadUSB is one sneaky bastard. I'd probably get a new mouse. You know... just in case... And if by any chance you get a new mouse, destroy that one.
https://github.com/robertfisk/USG/wiki
i wish there was a crack for hitman alert