Hi there,
No major problems that I can see, although the pages scroll horizontally at 800x600 (a resolution still used by more than 1 in 10 people!). So I'd be tempted to either rework the page width to be, say, 780 pixels across, or make the layout fluid so it stretches and squeezes horizontally with the browser window.
From a design perspective, I'd look at blending that header graphic a bit more into the rest of the page; it looks a bit "boxy" as it stands. I'd also suggest toning down the text colour - maybe #dddddd? - as the full-on white against the black background does strain the eyes after a while.
Hope that helps!
--
Matt Doyle, Elated
3rd Edition of my jQuery Mobile book out now! Learn to build mobile web apps. Free sample chapter: http://store.elated.com/ 
