I just got my machine yesterday, so I did download the latest versions of both the MS software and USB Overdrive.
Inside the MS control panel, it normaly shows a picture of what mouse you have, but that appears as a greyed out mouse with a red X. In USB Overdrive, when you press on the buttons, it usually highlights the name of the button you are pressing, but that doesn't happen either. The Apple System Profiler does show the correct name of the mouse hooked up to the machine. I've tried both hooking the mouse directly to the computer and to my 23inch monitor.