Hello Ernie,
My aplogies for the late reply.
There is no such thing called the SQL agent that you have to install. It is just a license that you have to install on the media server. The remote agent does the job for you. For example you need to backup a SQL server, you need to install the SQL agent license in the media server and the remote agent license on the remote SQL server. This applies for Exchnge, Oracle, Sharepoint and Lotus Notes servers.
I advised that AOFO needs a reboot because it is kernell driver which is installed(Veritas Snaposhot provider) to activate the features of the AOFO. Ideally you could also use the remote servers Microsoft VSS to backup open files.
Do you still have the issue? Did you try extra logging using SGMON?
Try the follwoing link.
Reboot the computer to reset the VSS component status.
Try another backup and let me know how it goes.
Cheers.