Gotcha, I think
Our SOA is all set up exactly the same as every other site on the box, so no problem there. The RaQ550 is also supposedly able to handle a couple of hundred sites and we're nowhere near
that limit, so no problem there.
It's mighty confusing. I think I'll have a mooch around the server just in case there's something I've missed.
Edit: Well I'll be f... blowed. On a hunch I restarted the server to see if there was anything that would do and.. both sites popped up straight away. It was almost as if our DNS entries hadn't been applied, even though I'd clicked the button that does just that.
Crap. I can't even blame Windows this time.