The problem comes up where you have duplicate GUIDs within MECM, How do you find them? You can do this within the console or within SQL. For this example, I will provide you with the SQL query to help locate computer who name has changed. This query will also help when a computer is reimaged but keeps the same SMSID

This query will display computers who host names changes.

Select
CS.Name0,
HCS.Name0,
HCS.TimeStamp
from
dbo.v_GS_COMPUTER_SYSTEM CS
join dbo.v_HS_COMPUTER_SYSTEM HCS on Cs.ResourceID = HCS.ResourceID
Where
CS.Name0 <> HCS.Name0