Chances are its a connection issue rather than a server load issue.
The server appears to be in Canada, which is certainly an odd place for it to be with a predominately UK site
When it seems slow go and do a ctrl + F5 NOT
an F5, the ctrl + F5 will load the page freshly without any cache. Time it, then subtract the 'Search took' time in the top right hand corner and you have your load time.
You can then go and do a tracert in CMD to see which hop (if any) is slowing you down.
Start > run > type cmd > enter key
windows key + R > type cmd > enter key (The run option no longer exists in the start menu for vista
When it opens type:
(18.104.22.168 is rib nets ip)
Don't copy and paste it in, type it.
Post a screen shot here if you don't understand the results, or PM me
Tip for JK, VB can use a separate CSS file instead of having it at the top of the page which is how it is now having looked at the source. Peoples browsers can then cache the CSS file, resulting in faster load times for all!