Virtual Machine backups fail when GRT is not enabled

Hi,

I have an issue with my virtual machine backups that I need to resolve. I am using Backup Exec 2012 SP3 to protect about 10 VMs running on ESXi 4.1.  The issue I have is related to non-GRT backups.

I do not wish to enable GRT for my VM backups, I am only interested in getting a basic VM snapshot backup, however if I do not enable GRT in the backup job settings, the job fails with the following error:

Completed status: Failed
Final error: 0xe0009541 - Could not connect to the vCenter server or ESX server. Please verify the credential supplied for login.
Final error category: Resource Errors

This error message would appear to be a red herring because if I enable GRT in the backup job settings, the job runs.

I backup GRT-enabled data with separate jobs and I do not therefore need GRT enabled for my virtual machine jobs.

Why does the virtual machine job fail when GRT is not enabled?  Backup Exec runs under a domain user account that has full Domain Admin privileges on the network, and Administrative rights in vCenter.

Any help would be apprecaited.

Thanks,
Steve...