Store breaks in IE8 works in FF

[technicalvault]

I was just pre-ordering the latest book when I ran into a small problem with the store. Everything time I try and use it in IE8 it seems to lose "state" when moving between pages. For example I sign in successfully but when I move to the next page I'm signed out and when I add something to my cart it goes and falls out. I have however managed to successfuly place my order in Firefox. I have also tried clearing the erfworld.com cookie.