If it does work in windows, check the game options to ensure that mouse buttons are mapped correctly. I am assuming that you have played prior to this w/o out a problem.
I am also assuming that it is a wired mouse. Check in Windows Control Panel to see if the OS recognizes the device as "working properly".
I would't spend too much time on it. Return it and get a good mouse. Cheap hardware = Cheap performance. If you have the money, it is worth it.
[SIZE=\"1\"]E6400 @ 3.4 , Noctua 120
7900GT @ 670/1680 , VF900
2 x 1GB Patriot 6400 @ 425
WD SATA 250GB
Neo HE 550
P180 / G15 / MX1000[/SIZE]