Sophos STAS "View Log" and "View Logging Events" errors

Greetings, 

I setup Sophos STAS Suite on a member server in a 2 DC environment.  I configured STAS to listen to one of the DC's for logons and logoffs. Everything appears to be working fine, but in the View Log and View Logging Events buttons in the STAS Suite I see a lot of these errors:

Error (0xcb8) monitor_logins: Cannot subscribe to event notifications

Error (0xcb8) monitor_logins: Event subscription failed (0)

These always seem to appear after a heartbeat check to the Sophos Appliance. Any ideas?

Also, is there any way to setup the Suite on a member server and monitor 2 DCs? Do I HAVE to monitor both DCs? Should I be monitoring the DC that holds to FSMOs roles? Does that matter?