I did however find an owner with "their music" in FLAC or OGG format and that didn't work. Sadly they were unwilling to change and we are waiting for the world to revolve around them.
Sorry I can't guess why in this case.
I have successfully synced via the Kies software to my new Galaxy Ace GTS5830 so as to send part of my music library from my PC to my phone. These files show in the "My Files" icon, ( the SD media-card ), but will not play from there. ( I get an "open-file" warning that "No application can perform this action ).