I finnally fixed a problem with hardware watchdog of bifferboard. Now bifferbaord does a proper reboot when being stuck by some reasons. I do expect a major boost in long term operational stability by that.
"Getting started" section (http://wiki.meteoplug.com/Getting_Started) does explain how to update your Meteoplug's firmware accordingly.
Newly ordered Bifferbaords with Meteoplug client preinstalled from the UK (http://bifferos.bizhat.com/meteoplug) will have this fix already included by today. You have a firmware with proper watchdog support, when it says "FW-Version: 1.1" or later on Meteoplug client screen (visible when you browse to LAN IP of your Meteoplug).