its not a backup if you can't transfer to another card Fred, and the audio does not work on another card from an SD Explorer backup, that's why Song Manager correctly ignores it, moreover if you already have working audio on the transfer card you lose it with SD Explorer, which Song Manager will not do. Thus its just a lot of wasted space in the sdb file, and on a card with audio this is a LOT of wasted space. I explained this in private mails a long time ago along with other things that needed sorting like the failure to handle slideshows. For example working on a pc SD Explorer will try to backup anything next to the private folder, once in a temp folder it tried to backup 7.5GB of various music files waiting for sorting in the temp folder along with the private folder placed there for a temporary quick transfer on the pc. It's fine as long as you put every private folder in its own dedicated folder on the pc BUT the backup function should really just recognise Private, Sd_Sound and Imexport folders.