Mouse acting crazily

I have a death adder running 1800 DPI with a 1000 Hz pooling rate. It works absolutely fantastic on other games and on the desktop, but when it comes to Crossfire, it is completely inaccurate. The explanation may seem vague and exaggerated, but I assure you this is true. I've googled the problem and found no solutions.

Basically, when I move my mouse in any direction, it quickly and frustratingly goes up, down and right / left at the same time. Aiming is made impossible.

I tried tweaking sensitivity, inversion and enabled Windows Pointer Precision, nothing worked.

Thanks for the help.