I have a strange problem. Sometimes when I move my mouse fast, it jitters crazily (mostly either not registering the movement or looking directly up/down). I use Zowie EC2 eVo Cooller edition (450 DPI) on QcK Heavy.

The strange part is that the jitter level changes from time to time. Most of the time it’s playable (meaning that I have to flick really fast for it to act up), but other times the speed cap for the jittering is much lower, and it happens at mid speed movements. The fact that it varies makes me think that it’s a physical problem (like dust on the censor/mousepad), but my mousepad is cleaner than any of you filthy slobs’, so that seems unlikely (:D).

Anyway, shit’s pissing me off, so I need your wisdom. How can I end this misery? It happens in every game (and even out in windows) and it happens on the all of the mouse’s three DPI settings.

EDIT:
I've just bought the EC-A version as nvc recommended and it works flawlessly at any speed both vertically and horizontal (the old eVo model ended up being utterly USELESS when moving the mouse along short side of the pad, forcing me to turn my pad and make really slow rocket jumps, derp). Guess the LOD-modifications on the eVo model did screw with the sensor.

Morale of the story: if you want a Zowie mouse grab the EC1-A / EC2-A with the Avago 3310 sensor.