Just got a Logitech mouse. Feels rather good physically, but the software doesn't allow me to bind a Media: Stop function to a mouse button. For some reason Media: Play/Pause is in the list, but Stop isn't!
After trying to figure out what to do about this I remembered that my old mouse didn't have any software that came with it in the first place, and that I had to install a tool to assign stuff to the buttons. And it worked with this mouse too!
Thank you, X-Mouse Button Control. (pictured on the screenshot)