The main menu doesn't seemed to scale to the edge of the screen in opera. The books & Articles menu item is quite large on a 1024x768 screen. Everything is also aligned to the left instead of center.
Also, the mouseovers for any links are not white underlines but rather blue/purple.
These are just cosmetic things, but these problems don't take a long time to fix so I thought I'd mention them. Opera is getting much better than IE, so it wouldn't be a bad idea to pay attention to this audience now.