Nice overall, but your header and footer are too wide at intermediate (netbook) sizes by 20-ish px (1.5em) or so, requiring horizontal scrolling. The main content pulls into line just fine, it's only the header and footer (sorry, don't have time at the moment to go through the CSS to find the problem, but I'm sure it's nothing big).
Hmmm... some elements still seem too wide at intermediate level.
When browser size sits between 800 (approx) and 1024 (approx), the content doesn't change at all, so the 1024 wide content just disappears on the right.
Unfortunately, when viewing the page source and css files, it's all in one lovely long line!! - not that easy to view and dissemble!
On closer inspection, it appears there are only two levels - up to 800 and greater than 800... but the content at 800 in the media query is set up for a 1024 screen... it might be better changing the threshold on your media query so it runs up to 1024 and over 1024 (well.. just below 1024 allowing for scroll bars)
This page that I'm working on has 3 stages which run 0-500-1024>
Does this make sense?