I cant see anything complicated about that site, there doesn't seem to be any flash or java on it and unless I'm missing something it all works fine in firefox but doesn't work in IE8 for me.
that said it's appalling HTML code! who on earth is using office to write websites, that page is about 4 times bigger than it needs to be. it also gets 188 errors on the W3c website check
http://validator.w3.o....co.uk%2Fringmerwatch
I think a rewrite of that site is in order using something that produces halfway decent HTML