Errors when using Powershell backup scripts

Hi all,

Ive recently setup a powershell script, as per the admin guide to run pre and post backup job. However we are getting errors in the EV event log at the start and end of backup:

Access denied. User is not in a role that allows '{STO} Can manage Vault Store Backup Mode'.

User: DOMAIN \ BACKUP_ACCOUNT'

This is mentioned in the article below, i have added the VSA into the 2 Arcserve services and restarted them and still it doesnt work, the account its using is still our normal backup account.

http://www.symantec.com/business/support/index?page=content&id=TECH141989

The article talks about adding them to the authorization manager as another solution, ive read the admin guide but cant see any mention of that.

Can anyone help with this?

Thanks