Stalker and other similar middleware, use that 79 MAC thru their IPTV platform. It is not the receiver's MAC
Them devices that do not have this iptv platform can not log on with a 79 mac as the server would know it is not coming thru a stalker platform, so would be rejected.
It must have the 78 so the server sees it as a emulation of said platform. And vise versa for receivers with the middleware. If they tried logging on witha 78 MAC, the server would see it does not compute as it is coming from a stalker application.
or something like that