Ok, this is what mcafee say:
Cause of this Problem...........
When a new machine has the agent installed it creates a unique GUID (PGP key) based on the MAC address and machine name of the box. That agent will then randomize it self with in 10 minutes to check back into the ePolicy Orchestrator (ePO) server. When it does, it will check the following (establishing a search order) to see if it has already been populated into the ePO console tree.
Without IP rules:
Agent GUID
Domain Name
Machine Name
IP address
With IP rules:
Agent GUID
IP address
Domain Name
Machine Name
If it finds an entry that is listed with in the search order it will populate under the correct group. If it does not find any of the above, it would then populate under the lost and found.
With this in mind, duplicate machines can be created when a new MAC address and/or machine name is introduced to the machine. Because that machine is creating a new GUID base upon the two MAC addresses or new machine, it will then try to check in, and would no longer be found in the console tree. This would then cause the machine to show under the Lost & Found, causing a duplicate.
Solution......... (but I guess you've done this anyway)
In order to remove these duplicates you would need to remove the older of the two machines, based on last update time in the console GUI:
Open the ePolicy Orchestrator (ePO) console.
Login as an ePO global administrator.
Right-click on 'Directory' and select 'Search'.
Browse the list until you have selected "Search for Duplicate Machine Names".
Start the search.
Compare the last update date of the machines and delete the older of the two.
Right-click on the remaining machine and select 'Move'.
Move the machine to the appropriate Group in the ePO Directory.