This really isn't a big problem or anything, but sometimes when i'm navigating around, my focus ends up on the jQuery logo on the top left, and i accidentally press enter at some point for some random reason, and i end up on an error page in a new tab. It seems to only happen when you aren't inside of a particular forum, such as when viewing recent posts.
You can recreate it by going to recent posts, tabbing to the logo, and pressing enter.
-- Kevin