Thanks for your replies folks.
I've been looking around at other sites and have had the 324 error come up a couple of times myself now. It comes up on Yahoo as well when using Chrome.
I suspect that there is an ISP peering issue going on in the UK at the moment, that would explain these browser timeouts. Peering is the mechanism that various ISP's use to connect their networks to other ISP's networks.
BT seems to be having problems ATM and as they are one of the major UK carriers that may be having a knock on effect throughout the network.
We're also looking into our own systems here.
CT