Are you saying that you have multiple buttons outputting the same codes? I've had a similar problem with my Kensington trackball. A couple of the buttons are duplicated and the rest don't work at all. It's a problem with the standard mouse driver, which doesn't properly support all the extra multimedia buttons on most modern mice.
Try the evdev driver instead; it will probably give you full support for all of your buttons. Just configure your xorg as explained here
. Note that evdev has a different set of configuration options and most of the older ones won't work; but in general most mice will work fine without any extra tweaking. You'll probably only need the Identifier, Driver, And Device path in your entry.