After the problems over the last week or more, everything for me is working well!
I've started posting new Observations again.
We have given the iSpot servers a thorough overhaul - and lots of love. In summary:
The database server has more memory.
The web server has new software.
Batch processing has been offloaded to a new server.
Many of the slow database queries have been rewritten.
Things have been tweaked to improve the behaviour under high loads.
The server load statistics are all looking much healthier, and our internal users are also reporting that the site is much more responsive.
iSpot is going to be on the telly tomorrow night, so we are expecting a brief surge in traffic - but we're confident that it will cope ;-)