Backed up to sparse image on Airdisk, but now can't select it again

[cbrandt]

here is what I did. I will repeat everything one more time to see if it makes a difference this time.
In Finder I opened the sparse image file so that "idisk daily backup" is listed under DEVICES.
I deleted the old scheduled backup for idisk dailybackup and created a new one scheduling it every night with the option to eject idisk daily backup "on successful completion".
I ran copy which it did successfully.
I then ran the weekly and monthly backups successfully as well since they usually run if another of the sparse image files was opened previously, probably because Finder is still showing their sparse image files. I did not change their option to eject because their sparse image volume wasn't listed on the choices of what I could eject "on successful completion.

rebooted
Tried to run idisk daily backup from scheduled copies and got same "failed to boot idisk daily backup" preceded with the same error message; "there was a problem connecting to the server"cindy's time capsule the share does not exist……."

I have the same problem on my mbp but that backup takes over 30 minutes so it is not as easy to test and retest quickly. But that is the backup I really care about since I take that computer back and forth every day and sometimes forget to plugin the external drive or to access the sparse image before I go to sleep.