That box is dead. Apparently the last update for infomir had in some sort of clone kill code. Even though the MAC Address indicates that it is an original MAG250, it is really a clone.
Only fix will be to get an usb ejtag programmer, a dump of the MAG250 firmware and you can google the jtag connections for the standard 20pin connector and burn a new image to the MAG250.
It is easier to google around for someone offering the service and weigh the pros and cons of either buying a new stb, preferably the new MAG254 or sending it in for repair.
