Hi Bonesy, nothing leaps out at me right now, but if it won't play up, you're up s#!t creek. A few suggestions though:
See if it's got "Auto over-the-air updates" (user menu, I think). Switch it off.
See if it's got "Watch Dog Timer" (WD or WDT) in the service mode. Switch it off.
Disconnect the Wi-Fi modem. Leave if off unless the punter uses it. Have been known to become corrupted.
Happy hunting, Bruce