Restore mailbox to PST failed

Hi,

I using BE 2012 with all hotfixs.

I am trying GRT to restore one mailbox which about 5GB to a PST file on the local folder on BE Server from 2011 Backups

The Restore Starts then after restoring about 1GB data - the job failed with these errors:

The Exchange Store service is not responding. Backup set canceled.

Connection to the restore target has been lost. Operation canceled.

Status:

Job ended: Monday, April 15, 2013 at 11:14:33 AM
Completed status: Failed
Final error: 0xe000ff12 - A communications failure has occurred with an Exchange Store resource.
Final error category: Resource Errors

For additional information regarding this error refer to link V-79-57344-65298

Noticed that the beremote.exe has been stopped on the BE Server

Noticed at event log : Event IDs 1000, 34113

and EVENT ID 257 :

A memory dump has been captured C:\Program Files\Symantec\Backup Exec\BEDBG\beremote.exe_6672_0.dmp

* I have Outlook 2007 + Exc Managment Console installed on the BE Server

What could causing this Fail?

Please Advice?

Thanks

Abed