This is most noticeable when clicking "Reply" on a post. The search bar and buttons get swapped around/stacked in several different ways. It differs even when simply hitting the back button on my browser and hitting "reply" again. See below picture.
What browser are you using? and can you confirm that the image just shows a header and nothing else? That is what I see but want to make sure.
Last question, this happens with the reply button and not the quick reply, correct?
Gah sorry Susan, I thought I included this.
I am using Chrome, Version 32.0.1700.41. Yes, this is seen when using Reply, not Quick Reply.