HTML/CSS - Internet Explorer floating issue

Reference: http://webfreak.co.nz/contact.aspx

If you go to this page on IE, the right block isn't floating inline, but it's all good in开发者_如何学C other browsers. What could be the problem here?

View the source for the HTML and CSS.

IE rounds up/down differently than modern browsers do but you aren't helping things by setting the left div to 57% but then the right div in px along with other elements. How do you know how many px are left? IE is probably rounding differently and thus dropping the right div down to make room.