MAC Client - adding a new MAC Client with the same name - over writes current Client

I do not have a lot of Customers with MAC OS but One of them just added a new MAC and the called the system name the same as a current MAC so when they downloaded and installed the streamer it replaced the current MAC with the new one - and then I could not get to the old MAC.... so they downloaded the Streamer on the old MAC and it over wrote the entry for the NEW MAC... 

Me things this is a BUG