I have a bunch of clients that were reporting as No. I regenerated the GUIDs and ran a Discovery Data Collection Cycle which seemed to take care of the issue. Now later after a Heartbeat Discovery and or a AD System Discovery, the discovery data is reset to null to the client related values. Why? What is happening here? Thanks!

Is the maintenance task "clear install flag" running?

Yes. Period is at 14 days, Sundays. Heartbeat is set to 7 days.

Can you please double check if the MP is working and heartbeat DDRs are making it to the database? Just initiate a discovery data collection cycle on a client and check the proerties of that system in the admin console then.

How can I double check the MP? Client=Yes ddrs I have checked show MP_ClientRegistration. These machines in question as Client=No do not. I don't see any problems in Site Status relating to the MP. Heartbeat DDRs are making it into the db, but these particular clients that showed a client installed, the heartbeat ddr wipes out or replaces the ddr with null values. These machines I had regenerated the GUID, then ran the discovery data collection cycle and then they looked fine. I will run it again and double check the MP Registration. Results: Found no MP Registration. One a particular machine I am looking at was discovered by AD Disc, client values ae Null. No MP Registration. This is one that was reporting properly after a regen GUID about two weeks ago.

I believe this is a DNS issue and fixing them one by one so far. It appears our DNS servers are not communicating with each other correctly. The DNS in the same location as the SCCM server needs to be the primary DNS on the machines in question. As I change them and run a Discovery Data Collection Cycle locally, the DDR on the server updates in minutes. Yet another failure of our infrastructure and not SCCM... Consider this an answer. Thanks again for the input Torsten.