Win8 odd mouse behavior

[Arkangyl]

I've been running into an odd issue with Windows 8, whenever I go to select text, or move a window around (any behavior where left-click is held down and I move the mouse) it seems to lose and then re-gain the left-click input.

i.e. I'll hold left-click and start moving a window, the system will then think I released the click, keep moving the cursor with my mouse movement, and then re-gain the click input. So i'll be moving a window, and then i lose my grip on the window and it jumps to a file in the window (that my mouse happened to go over) and decide to move that file...

any thoughts?

relatively new Win8 install, the only app I've put on recently is Launchy which I've tried disabling to no effect. Mouse is a 3 year old Logitech G9x that seems to be working fine otherwise

[Arkangyl]

to conclude: it was the mouse

[BlindShot]

My Logitech 510 has problems like this out of the blue?