Since version 2.33 Mp3tag supports Unicode. For compatibility with devices, which do not fully support unicode, in these versions Mp3tag offers the option to write ID3v2 tags in ISO-8859-1. (see /t/2785/1. This worked fine for a long time with the Archos Gmini 200 e.g., since this player can read unicode tags only partly resulting in an alphabetic sort order when playing a directory (should be ordered by track number).
BUT, starting with version 2.37a (?) ISO-8859-1 ID3v2 tags seem to be written differently, since the sort order on the player is mixed up again. When I use the old 2.32a version (which obviously write ID3v2 tags in ISO-8859-1 by default) to overwrite the ISO-8859-1 tags from v2.37 everything is fine again. Of course mp3tag runs on a system with unicode support (XP SP2). Just in case that this has low priority, it would be also helpfull to make v2.36 available again, wich as far as I remember worked o.k. with respect to the above issue.
Thank's a lot for the great program!