Update... Erm, one more reboot, (re)accept the license and all back to normal. Post below left for the curious.
Ok, so this is weird, and is either 'something quite interesting' or 'so embarrasing I should hide'. Using a Meteobridge pro, wired network, the web page no longer shows the login message ...
Once the systemload has peaked it sometimes doesn't recover until a reboot.
I log into mysql each minute most of the available variables, including CPU load. I've (this week) switched off logging to all other external weather nets (was using cwop and met office) to try and ...
I have a meteobridge pro receiving from a Davis pro2 that only logs data to a mysql db. It frequently (and now permanently) has a system load over 100%. As a result, it seems to 'miss' rainfall and other data. RF reception is -61 (though don't know if this is good or bad!)