Restore Options tab is blank and "no restore options available for this plugin" message. (4046348)

Title: Restore Options tab is blank and "no restore options available for this plugin" message.

Symptoms:
When we select a file or a folder to restore, in the Restore Options it displays no options and instead it displays "no restore options available for this plugin".
When we launch the job, it fails with the following errors:

Job Message 2011/04/28 14:32:10 3049 Data Plugin FRPARMBX003 File System 7.5.8 restore
Error 2011/04/28 14:32:10 3049 Data Plugin FRPARMBX003 Invalid restore options
Error 2011/04/28 14:32:10 3049 Jobs FRPARNETVAULT Fatal error: Restore failed

There were many backups running at this time, but when there are only 10 jobs running, it displays the Restore Options as normal.