We're being overrun by a spider-bot for a Chinese search engine called Baidu - which is very aggressive and is using up all the server resources by flooding it with too many requests at once.
I need to install some software to combat it (block its access to CC) which I'll hopefully do tonight.
In the meantime I've reduced the number of simultaneous requests the server will handle, which will lead to a bit of a pause here and there as requests are queued, but it should make CC usable - hopefully!!
Cheers,
Shaun