Make sure that AOFO is taken off the job itself, and in Tools --> Options. Ken is quite right there.
If you need to backup your data in 1 shot, that is the only way around it.
However Dev T has a good suggestion on breaking your data up with the IS running separately.
If you don't know how too, read up on this article for help...I have done it on 2 sites already with good results.
https://www-secure.symantec.com/connect/articles/backing-databases-and-files-same-tape-separate-jobs-using-backup-exec |