@Cass
AFAIk if you want (like me) to attempt an "incremental backup", you must take OPEN your session.
You''ll be able to read the data ONLY using the CD burner itself and not with the CD player.
Only if you'll take the Session open, you will be able to update the backup, how? . . . i don't know.
Ciao
PS- anyway i'm still useing the Multivolume method, not the best but usefull.
When i insert a Multivolume in the CD drive, a window appeares with all the Volume names.(you must choose Multivolume from CacheCDFS prefs).