a debian user reported that Thunar User Customizable Action didn't recognize "ogg" files as Audio Files. If you add an UCA wich should apply to all audio files, it doesn't show for ogg files while it shows for mp3 one.
If you need any information more, please ask.
Thanks for your time,
Fixed with revision 26395.
2007-11-28 Benedikt Meurer <firstname.lastname@example.org>
* plugins/thunar-uca/thunar-uca-model.c: Properly recognize
OGG files as audio files. Bug #3604.