yeah, the MAC was registered mate - i think it must be the router one, because it surely wouldnt be able to pick up the IP addresses if it wasnt?? the whole thing was reset after the firware update, it just seems to have lost the settings that told it how to connect to the internet. gutted!
which is probably what would happen. a firmware upgrade is flashing the ROM with new data - like setting to the detault settings - so it will need setting back up.