Change your doctype to either
HTML Strict or an
XHTML Transitional doctype.
Reduce the width of your navigation class to 130 and then everything below it. The .navigation li a { and.navigation li a:hover { should be 120px or around that. You need to take borders, padding and margins into account. That the box-model hack. IE7 got some of it right and FF has been doing it right all along but Ie6 ... well ... it's IE6 :P
You should code your site according to Firefox and not IE. Firefox will display your code as you write it not as it is intended like IE.
There's alot of unnecessary code in that
CSS too. Stuff like this
Code:
.content
{
width: 452px;
border-top-width: 1px;
border-top-style: solid;
border-top-color: #000000;
border-left-width: 1px;
border-left-style: solid;
border-left-color: #000000;
}
can be reduce to this
Code:
.content
{
width: 452px;
border-top: 1px solid #000;
border-left: 1px solid #000;
}
Ryan has a really good article on
Proper CSS Shorthand that you should definately look at.