Any job ran with an assigned login, will show in the task details that either the login was blank in history or "no selection" during the job run time.
During run time: Double-click on job in backlog->'General' tab shows Login as 'No Selection'
After the job has finished: Double-click on job in backlog->'General' tab shows Login as a blank/null value.
This is a known issue and is being evaluated for inclusion in a future service pack for Applications Manager. The job does run under the correctly assigned login and can be confirmed by viewing the output file.