Here is the required stuff in minimyth.conf
and I have custom lircd.conf and lircrc files that minimyth grabs.
This all works GREAT and you can even ditch the flimsy xbox remote and program a Logitech Harmony remote for example.
You can either figure out which pin is which when removing the controller connector, or you can test for continuity between an obvious ground point and each outer solder points to find which is pin 1.
The following link has a basic lirc file for xbox remote, but when I programmed my harmony it supported way more keys so I added to the file manually.
http://www.mythtv.org/pipermail/mythtv- ... 77952.html