[CSS] Internet Explorer 6.0sp1

I am writing this page to be as compliant as i can make it:
http://figmentenygma.com/beta

there are several issues with it, but the one im concerned with most is the width of the two navigation bars at the top...
in Opera, Mozilla, and Netscape (all Win/PC) the bars go to the left edge of the screen.

But on IE they do not, why is this? and how can I fix it?

I have tried setting the right: 0px and width 100%, that worked except it overlaped my other divs, and is thereby not ideal.. id like not to have different z-indexes.
I also tried setting left: 145px and right: 0px
and I also tried a simple width: 100%;

none of them were good solutions or worked at all, im wondering if this is just a bug in IE, or if its my code, Ive only been doing CSS for a week and a half now.. any help would be great..

:Figment