First, I see tons of errors being reported back to the ZCM server about:
Could not find a handler associated with:

and then it'll list things like:
Printer, etc


But I don't HAVE any DLU or printer or bookmark policies. So where in the world is it thinking I have them?

Then those errors will mysteriously/randomly go away and the next day I'll get:

There was an error while unenforcing group policy
followed by:
The action grouppolicy (ID:grouppolicy) failed due to the reason : failedToEnforcePolicy, however the action is set to continue on failure.

This is with ZCM 10.3.1 on Windows XP workstations.