Not to mention that when you change your sig it automatically updates in every post you've ever posted, so there's never a need to "test post". Simply go back and look at one of your old posts, and it should show up.
I was able to ignore this post for all of 24 hours figureing the entire thread was a "got ya" post. As they said, the sig only shows on the first message per page and it automatically updates as you update including Avatars.