Alan's script uses the Get-VIEvent cmdlet to find the entry for the creation of a guest.
By default the cmdlet returns 100 most recent events.
If your guests haven't been created recently, the VmCreatedEvent will not be found and the script will mark the user as 'Unknown'.
To test, make a new guest and run the script again.
For that recent guest you should see the custom attrbutes appear.
____________
Blog: LucD notes
Twitter: lucd22