Modifying playlists .pls files

Is there a small freeware app that I can modify playlist .pls with that were created by Sonique Mp3 player?

Thanks!

 

If you have the option to create playlists? it should allow you to modify them.

 

For some reason after I have added some more oggy vorbis files to my playlist in Sonique then add a couple of mp3s to the list and then save it the list is ok but when I close Sonique and reload it those oggy vorbis files are missing from the playlist?The mp3 files I added afterwards are there but not those ogg files?For some reason when the program shuts down it doesn't save those ogg files even if I add them after the mp3 filse I added it still doesn't save those .ogg files to the .pls.