IE 8 layout problems with website

Hi, I wonder if anyone can help me, Im using the careta theme. It works fine on Google chrome, safari, ipads etc. On internet explorer however, it falls apart, header doesnt fill screen, menu bar dissappears, photos appear in the wrong places… you get the picture.

Never had this happen with other sites, so no idea as yet how to fix it.

Can anyone advise on this?

How can I to stop this happening?

Here is a link to the site: