Aha! The mysteries of the mudcat. There are in fact two identical mudcat sites. I think the official term is "mirror sites" - I think they're in parallel universes that happen to be running in synch for the time being.

Anyway, when for some reason the http://www.mudcat.org/ site is playing up - giving unobtainable, or being remarkably slow, it's worth trying the other one, which is http://ragtime.mudcat.org/