Bug Report:*Simultaneous question syndrome* A picture is worth a thousand words - http://assets.openstudy.com/updates/attachments/4fc0fbd3e4b0964abc82fcc9-foolformath-1338047478067-uniquebug.jpg
How long did that last? Did you only have one tab open?
I don't remember about tab, but it was gone after a refresh. I have encountered this twice at the time of writing this post.