Comment 26 for bug 61105

The thing unclutter conflicts with is SDL's relative mouse input. If you
export SDL_MOUSE_RELATIVE=0
before running an SDL game, the mouse won't jump. OTOH, an FPS like nexuiz will be unplayable because you won't be able to turn freely! But this does confirm that it's SDL's relative mouse input that is broken by unclutter.

 So it has nothing to do with xserver-xorg-input-mouse