Have you encountered Event 8390 in the Enterprise Vault (EV) Event Viewer?
Event 8390 can occur in EV for numerous reasons with many accompanying event IDs. Before you create a support case with Symantec, the solution you seek may have already been documented.
We have created a digest that illustrates some of the frequently encountered occurances. The article contains links to 14 Tech Notes, which document detailed information on diagnosis along with the applicable solutions.
Please see www.symantec.com/docs/HOWTO83884
Good Luck!