Scrolling is seriously broken. (ff3/OSX)
You display some articles, then I scrollwheel, and things go bezerk. I scrollwheel down and it jumps up and down like a kid with hyperactivity disorder. There's no scrollbar - I have no idea where I am in the list of stories. Trying to match up where I was with where I am now is pretty hard. You've put up/down/top/bottom buttons at the very top and called them "Navigate".
So you've reimplemented a scrollbar (Standard browser UI component), but very very badly.
Up and down keys don't scroll properly either. If I hold down a key, it should keep repeating. Pressing a key should scroll the amount I am used to. You seem to be scrolling by a lot, on keyup - not what people expect.
Sorry, but I just hate it when people reinvent something that already exists, is standard, and works. Especially when their implementation is completely unusable.
Why not just use a scrollbar like people expect?
Also when I click on an article to read it, I expect to click [back], to go back, instead of clicking on [return to the reader]. Once again, ignoring standard browser usability.
Also if you try to open an article link in a new window, or copy it to send to a friend etc, it breaks, and you land at the homepage (I assume you're using onclick etc). Another usability flaw.