Also worth noting (should have mentioned it in the readme but I forgot)
If you are copying your data files over from your pc install, make sure you don't copy over the q3config.cfg file.
Some options that you might have set in your pc game will cause problems if you try and use them on the xbox.
The only q3config.cfg that should be in your baseq3 folder should be the one from the release distribution.
so i assume you mean a clean one from a fresh q3 install, with no modifications made inside the pc game?