If it's what I'm thinking ..... have you got a bigger screen?
I'm on a 22" (1680x1050) and there is more white border that page
the fancier the site .... the more likely it is to be working in a fixed size frame (generally 800x600
the old text sites just fill the page .... but ab, bbc etc go for artistic effect (white is the new black!)
the pictureless boxes - delboy could be right .... the latest browser security and privacy settings generally disable java by default