NTI Shadow will only work once

[TJW]

I have set up a backup job using NTI Shadow to back up my laptop to my ReadyNas DUO.
I have set it up to run once a week and maintain 1 revision.
The backup works once OK.
Whilst then working off line I get a Shadow error message that the destination is unavailable.(understandable)
When I re connect to the network the backup job starts and freezes, and no amount of stop/enable/disable/start commands make any difference.
If I then edit the backup job, changing nothing except the final destination file, the backup will run again, and we start again.
I am sure that I am missing something...can anyone help?

[TJW]

Have I put this in the wrong place?