Actions for extra mouse buttons
I'm using a Logitech MX 500 optical mouse via USB on a Debian Sid installation. I've got X configured so it recognises 7 out of its 8 keys (xev shows the correct ButtonPress/ButtonRelease events).
The MX 500 has two thumb buttons (buttons 6 & 7 in my layout) which are quite convenient for navigating browser history - one for going "back", one for "forward".
The point is this: At some point, this worked fine, i.e. I could use these buttons to go back and forth in Konqueror and Firefox. This behaviour suddenly disappeared without discernible cause - now the buttons just generate events, but Konqueror/Firefox don't handle them.
Any idea how I can assign useful actions to my extra mouse buttons?