Comment 12 for bug 241973

That would be classed as a bug with your hardware, perhaps a firmware update is required. The ogg standard now primarily uses .oga for audio, and .ogg is kept only for backwards compatibility, see http://wiki.xiph.org/index.php/MIME_Types_and_File_Extensions . I too have a hardware player that recognises .ogg and not .oga, so I keep my files as .ogg as well (for now).

I believe it's more important to adhere to the standards rather than keep using .ogg indefinitely, just to keep some hardware players happy. I suspect only a fraction of users with .oga files will have .ogg hardware players, and those that do would probably be aware why an .oga file doesn't work.