My mouse has more than one button, but only the "primary" button works. Why can't I get the other buttons to function?
All mice default to the "dumb" mouse condition (and act as if they have only one button). In this case, the software that controls the additional buttons on the mouse is not installed or is not functioning properly. Make sure that the related software has been Carbonized or is written in Cocoa; the mouse won't be able to use Classic software. Check the manufacturer's Web site to make sure that you have installed the most recent version and any patches that have been released. If not, download and install the revised software. If you have the most recent version installed (and it is Mac OS X?compatible), you probably have some sort of conflict with another piece of software or hardware. Check the support area on the manufacturer's Web site to see whether you are experiencing a known problem.
Also, try installing the mouse in another USB port, such as one that is part of the Mac itself. Rarely, a USB hub will have difficulty passing on the required data. Moving the mouse's USB connector to the Mac will eliminate a USB hub as the source of the problem (assuming that the problem doesn't go away by installing a software update).