[OpenAFS] can't obtain PAGs on Windows Server 2008R2

[John Perkins]

One of our Server 2008R2 systems is reporting a lot of errors like this 
during login:

Event 1008, AFS Logon: AFSCreatePAG Failed IOCTL_AFS_AUTHGROUP_SID_QUERY 
Error 0x00000490

Not a big deal when logging in as administrator and getting a desktop, 
but we suspect we're seeing problems when our VMware VM backups fire off 
on this host and create unattended sessions for individual VM backups.  
Stopping the TransarcAFSDaemon service while backups are running seems 
to improve the reliability of the backup process.

The administrator user exists in domain AD (ad.cs.wisc.edu).  We do use 
integrated logon, but it is disabled on a per-domain basis for domains 
LOCALHOST and AD in our case with 
HKLM\SYSTEM\CurrentControlSet\TransarcAFSDaemon\NetworkProvider\Domain\<domain>\LogonOptions 
= 0x0 registry keys set to disable integrated logon for users in those 
domains.

Is the above AFSCreatePAG error a critical error, and is there a way to 
tweak the system settings to eliminate such errors?

John