Backup Exec and Puredisk OST

Hi I am trying to configure Puredisk OST and Backup Exec. Windows 2008R2 Backup Exec 2010 with latest updates & puredisk 6.6.0.308. I am using the root password on the Puredisk server just to get going but I ma getting an error "unable to connect to the OST server" no other errors [as far as I can see]. When i try the system logon account i get an authentication error on the puredisk event log and an "authentication error on OST server" on BE console. Has anyone set this up sucessfully? what steps did you take to get this working?? do i need to confgure anything on the Puredisk server? any help gladly welcomed. Mark.