Thanks all.
Essentially, my predecessor, who was sac... who left 3 months ago had some wild idea of setting up a new Information store for Archiving. After he left I found 5 mail boxes had been set up in this store. I moved them to the main store and took the new store offline, without realising the consequences. The idea was to see if we needed it, and if not, delete it.
So, when I ran the backup as I said, the normal store backed up fine (successfully as posted), but when I finally found where to read the report, I saw that the other store which I had forgotten about was failing because it "had to be mounted" as the report clearly stated.
We deleted this store, ran the backup again (which took 1 hours!!), and all is well again. Only a nrmal number of logs.
Thanks to all of you who helped. bk66md had the right idea, though I had already discovered this before seeing his post. However, please note that the app event log was not very forthcoming in this situation. It was the report in ntbackup which was useful, and now I know where this is for future refernce. We live and learn!
Will
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