The thing is that Logitech G9 Mouse doesn't have MAC supported drivers provided by the manufacturer and that leads to most of the delicate functions of the mouse not being available. (e.g. Side mouse buttons 4 & 5, DPI changing +/-) Logitech Control Center (LCC) for MAC does not let you configure it at all of course either. (since it's not even recognised/available) So after reading a few posts about the matter...it turned out that you "should" normally be able to configure all the mouse's basic buttons (apart from DPI changing) with "SteerMouse". But even after using that program my Side Mouse buttons number 4 and 5 were not even recognised (using the program a bit urselves should give you a clear idea of what i mean). I even used the "reconnect" button several times (button used for exactly such occasions), unplugged and plugged-in again the mouse, restarted MAC but with no effect... If anyone knows what could be wrong then i would be more than grateful to hear some possible solutions to the problem.thank you in advance. P.S. No i m not using "USB overdrive" at the moment and it's 100% certain that it is unistalled completely.