Generally; optical mice don't fair well when gaming, they can't keep up with the movements required in games (especially in FPS games).
http://www.wikivs.com/wiki/Laser_Mouse_vs_Optical_Mouse
newegg has some decent laser mice...also try looking for wired laser mice, better sensitivity.
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2010290065%201083607056%201083407048%204025&bop=And&ActiveSearchResult=True&Order=RATING
I received a iMicro MO-5013P today as a replacement mouse. Sadly, the mouse works perfectly in any other situation besides gaming.
The PS/2 mouse is unresponsive when playing games. I was just in TF2 when the mouse wheel would act on it's own and then the entire mouse will not respond for thirty seconds after. Not to mention how it will randomly stop responding mid turn in other games. I've disabled V-Sync and scaled down on my settings, but nothing works.
It's a iMicro MO-5013P PS/2 mouse. I was thinking of a driver update, but the iMicro site provides none. Should I try the Basic Optical Mouse drivers from Microsoft? Which mouse should I select when the driver installer prompts for one?

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