The button on the bottom left just above thread display option is only partially visible using opera , not sure in other browsers.
And I thought it was just Chrome. I honestly have had trouble with this as if I reload the page it will sometimes align correctly, sometimes incorrectly, even when rendering the same page. I'm wondering if it's a height issue related to the fact I added Facebook and Twitter to the bookmarks box at bottom left.
I have the same issue in Opera, also the icon legend and posting permissions boxes dont have the same combined width as the thread display options which looks a little odd. Nothing major though.
Same for me with IE8 I suggest ISI to stop the rfactor2 developement and sort this out first.........