steelseries kinzu v2=lag

i have been lagging when i play ET for almost a week now, tried everything i could to fix it...and just 15 minutes ago i decided to change my mouse from the new one i bought and had for almost a week now to a regular pc mouse and it was the gaming mouse that has been the source of my lag this WHOLE TIME.

have you guys ever had a problem like that before?

any suggestions on how to fix this? it happens every time im shooting, in a duel, throwing nade etc..the more i use it the more i lag.

thank you in advance :)