Bah! My machine's primary (ie the decent quality one) gfx card has blown up. We suspect it was when the crazy german guy in our office was wiring us up to the building's UPS. We have our own UPS in this office and we'd been told that there was a building UPS and special plugs we could use to wire ourselves up to it, so he started work on wiring our UPS up to this.
At least, this is what we thought.
It then transpired that he was working on the stuff that wasn't on UPS - which included my power draining monitor. I wasn't paying attention as I was checking LJ, but then the power came back so I switched back to looking at the monitor. Which was reporting no signal. After much hoofing about, it seems the machine got upset (another co-working mucking about with keyboard whilst I was out of the office) and I had to get someone technical in to have a look at it.
Luckily the machine has 2 gfx cards and after rebooting and fixing the machine blind, he managed to get the machine to use the other gfx card.
Of course the moment he got it working again, we had another powercut. Joy. I really do love working here.