i have a friend who experiences a certain problem on occasion while playing CS or DOD. he will fire his weapon and nothing will happen. he can move and everything else, but can't fire his gun until he jumps using his mouse wheel-button. he can change weapons, but can't select them until he jumps. it's like his fire button becomes jammed until he uses another button. his comp has been completely formatted (for other reasons) since he first had this problem. of course we've tried different mice (ps/2 & usb). his and my comp are similar except he has an HP mobo and uses the arrow keys instead of w-a-s-d. could it be either one of these things?? his CS is retail and updated. can't think of anything else. thanks in advance.