IE hacks...?

I am making a website for work, (im a student on my work placement year) which needs to be viewed in both Mozilla and IE, I have been checking the progress of the website as I build it in IE and Moz but the most recent build progress has caused the page to go all over the show in IE

here is a link to the site http://www.suz-j.com/work/indexnew.html
as u can see in Moz it is fine, IE it is a mess.

I think it has something to do with the latest additions which are the two boxes with green borders and the small menu tabs.

the css for these are #intro2, #intro3 #tabmenu

I am not sure at all how to fix this in IE so any help would be much appreciated !

:nerd: