You haven't by any chance got DHCP turned on on both routers have you?I have 2 routers, one is on a local network only and the other router is connected to the internet, I just plugged the humax in to the router which is connected to the internet and it has stopped crashing. I unplugged it and put it back in the local router it still appears to be ok. its a mystery.
I found my HD-FOX-T2 started crashing after a minute watching the various channel 4 channels, with no network connected. But I did have an ethernet cable plugged in -- nothing on the other end. Unplugging it cured the problem.It's no mystery. The More4 stream was causing the Humax to attempt an Internet transaction, but there was a network configuration abnormality which is not handled properly in the Humax code and crashes it. Your actions appear to have resolved the network configuration.