Well, I guess its not really at the bottom of the page. I should have worded that better.
Its the check boxes below the post box. The second box should say "override double post"
Hey, for the profile that you just made in the freebie thread, i'd suggested dividing everything into several posts, rather than just one. It looks a bit too crowded.
And if you arent sure how to override the no double post thing, you just "go advanced" with your post, and there is an option at the bottom to turn the double post off for that post.