Hi,
Thank you for your post.
As far as I know, MOM uses discovery rules to determine what the “desired” state of an agent is. When machines are deployed via the install/uninstall wizard or approved manually via Pending Actions a corresponding discovery rules is created for the machine with a desired state of Agent-managed. And FCS has a auto-approval feature where is hourly queries for manual installations and approves them. For some reason, the discovery cycle MOM thinks that you have deleted the discovery rule and no longer wish the computer to be agent managed. If the MOM servers action account is an admin on the client machine it will try to uninstall the agent on your behalf. If it is not, it will place the computer in Pending Actions with an action for uninstall.
Regards,
Nick Gu - MSFT