WP-Cache
I just realised that the shiny WP-Cache plugin I installed wasn’t actually functioning (it’s the only plugin I’m aware of that doesn’t start working when you click ‘Activate’ in the plugins list, noooo, you have to specifically activate it in its own config screen). Anyway, the short story is that it is now turned on, so if you notice anything strange (like a blank page for example) drop me a line using the equally new contact form (WP-Cache is set to leave that alone for other reasons).
EDIT: I’ve disabled WP-Cache, it was screwing the Technorati Tagging. That was short!