Mouse problems

[Shinobi]

TEH MOUSES WONT WORK.

Whenever I click on any of the "left/right arrows" on the advanced video settings menu, the mouse pointer moves to the centre of the screen and is out of line with what I'm trying to select. See vid below:

http://www.shinobi.talktalk.net/menu1.avi
http://www.shinobi.talktalk.net/menu2.avi

(Vids may not play in WMP, they don't for me.... god knows why)

...anyone else experienced this??
Running Win7 x64, with a Razor Diamondback 3g Laser mouse. Yes I have the latest drivers.

I also vaguely remember doing some registry fixes to remove mouse acceleration a few months back, but that's irrelevant, it just started doing it today.