Mick Waites posted a new release of his excellent GBA game, heres the info:

Version 1.03 of Xor is now available for download. This version fixes the problems in three of the new Procyon's Mazes maps. Two of them could not be completed and a third had map quadrants missing. All have now been tested in this new version and can be completed.

More info --> http://www.gbagames.dsl.pipex.com/