Root credentials fail for some but not all VMs running on a single ESXi server
I have a client running Backup Exec 2012 on Server 2008 R2 Enterprise Ed. I am configuring the server to connect to a single ESXi 5.1 server that is running 6 different VM's. All the VM's are on the domain. The ESXi server is a stand alone server that is not clustered or connected to vCenter in anyway, so authentication is limited to local VMWare users. I have configured a user (several in fact) for root and am using it to authenticate to the ESXi server so the servers can be backed up as VM's. The credentials will work to connect to the server, but randomly fail when trying to connect beyond the ha-datacenter. Testing credentials will vary the servers that are successful and fail.
As you can see above, BAL-APPS is successful, but the other 5 servers on the same ESXi server fail. I have rebooted the server. I have recreated the credentials several times. I cannot come up with a reason why it works for some but not all the servers running on the same box. Please help.