Actually, whenever I tried to remap Crossbow/Grenade/etc. to anything but the middle mouse button, it would not work. I tried multiple other mouse buttons and different keys on the keyboard and nothing worked which sucked because I don't ever use that button. Had to even remap my mouse's onboard settings just to leave it on the stupid middle mouse button. If you find a way to get it to work on ANYTHING else, please let us know.