This is a commonly occurring problem with real band,
it has been asked to to have real band default to save as SEQ on every save,
but it has not been implemented.
Band in a box only has one audio track so when it asked what audio track to save this is what it does, where save as SEQ with save all the tracks.
Did you look in the backup folder in the real band folder c:\realband\RBBackup, if it is there as a *.bks go to file - open special - open backup file