Well - as you can see, the website is back online -
To alleviate any conspiracy theories, this is what went wrong..
On Monday (30/10/17) evening, there was a brief power interruption issue, at the secure data centre where our web server is located. Normally, this would not be an issue, due to alternative power backups.
Unfortunately, the event caused a failure in the server, and it would not reboot correctly - so it was decided to replace the server for a more advanced/resilient one. The hardware replacement went well, and was done quickly, however, a number of software compatibility problems occured, once all of the data was transferred.
Finally this morning, I had to undertake repairs to the 'sessions' part of the now rather large database.
Hopefully, all should now be stable - if not even better than before. But obviously we'll continue to monitor the situation.
Apologies to all for the inconvenience.