Does your MP Control Manager log have nothing but errors about a machine not registered to the site?
Symptoms
Component: SMS_MP_CONTROL_MANAGER
MP has rejected a policy request from GUID:XXXXX-XXXX-XXX-XXX-XXXXXXXXXXXXXX because it was not approved.
Solutions:
Locate the machine by running a SQL query on the database:
select SMS_Unique_Identifier0, Name0 from V_R_System where SMS_Unique_Identifier0 = 'GUID:xxxxx-xxx-xx-xx-xxx-x'
1. Mixed mode: Check to see if machine has been approved in the console
2. Native Mode: Check to see if the client is installed correctly or registered correctly. Also check to make sure the client certificate is correct on the machine
You may need to uninstall the client or repair it if the the data in the console looks correctly. Hopefully the problem will stop after a while and logs will clear out.