Its a Logitech mouse, part of a duo set with the keyboard. I also tried my wireless notebook mouse, and that didn't work either. No third party programs, though the set did come with Logitech's setpoint software, which lets you configure your keyboard and some mouse buttons.
EDIT: Got a work around. Went into Logitech's software and set the left/right tilt of the mouse wheel to middle mouse button, and now it works fine.