Hello Christopher,
You had mentioned earlier that the backup fails on several servers, and not just one. Since when did the problem begin occuring? What are you backing up in this job?
Regarding error 57860, check if the following technotes apply to your environment. If yes, you can follow the steps in the technotes below and check if that helps.
Title: In the event viewer, Event ID: 57860 "An error occurred while attempting to log in to the following server... SQL error number: "0011"" is seen when backing up a server with SQL installed.
http://support.veritas.com/docs/264616
Title: Event ID 57860: "An error occurred while attempting to log into the following server..." is reported in the Event Viewer while a backup or restore job containing SQL Server data is run.
http://support.veritas.com/docs/251942
In any case, as i had already said, 9.1 is a free upgrade and resolves several issues present in the earlier versions. So you can try that too.
Get back to the forums in case of any more queries on this.
Note : If we do not receive your reply within two business days, this post would be marked ‘assumed answered’ and would be moved to ‘answered questions’ pool.
Regards.