SFM Mouse Drifting Problem

[don't spookily ask]

So, I opened up SFM, loaded up a map, all seemed well, got the cameras set up and everything, until I pressed F11 (hotkey to go into game) in order to put my Scout in position, when I noticed my mouse started drifting. I moved my mouse a little and it would keep moving. Impossible to aim, or do really anything during that mode (or recording mode). Now, before you say "get a new mouse" that's not the problem. It doesn't drift on anything else (Need to test other games) except SFM's ingame mode. It doesn't drift on the menus or cameras either. If it helps any, I'm using an HDMI cable to connect my laptop's screen to a TV, and I'm using a Razor keyboard instead of my laptop one. I'm using the same mouse (Logitech wireless) plugged into my laptop. Help?

EDIT 1: I validated the SFM files. 36 files failed to validate and were reaquired - so I loaded it up again, pressed F11, and my mouse was still drifting. Validated it again, and 36 files failed to validate.

[don't spookily ask]

Bump

[spyware]

I'm also having this problem, wtf?

[DABERNAR]

Same

[surfer171]

What type of mouse and surface you're on is important to answer.