The fixed header is a complete waste of space. Why is it necessary? It's frames all over again, it's like a web design straight out of 1998. Also, is the right-hand sidebar supposed to contain ads? I can't think of another purpose for it, but I don't feel like turning adblock off for long enough to find out...
There is no side-bar to the right. The site expands to 1400px. After that there isn't anything meaningful to place on the right side (other than for the sake of doing so - but thats just clutter)
