So after investing time into finding out how to solve this problem I stumbled across a good solution, even uses em's. It works outside my blog, but for some reason it refuses to apply in my blog.
The code (from http://www.svendtofte.com/code/max_width_in_ie/);
border:1px solid red;
document.body.clientWidth > (500/12) *
I'm attempting to apply this to ".post p" from K's default theme (as the base theme code.)
I even dropped the .post out, and styled all my p's this way, the IE expression doesn't execute, the css comes out, see the p’s with a red border..
Is there something in wordpress that would prevent the expression from working? Any special places you're supposed to put it?