I was working on http://campus.codeschool.com/courses/front-end-foundations/level/1/section/1/marking-up-lists . I was entering h4 tags and kept getting messages saying that I did not enter h4 tags.
Perhaps it was related to my use of Firefox with NoScript, AdBlock Plus, Privacy Badger, and Certificate Patrol. I disabled most of them for the codeschool.com site and restarted Firefox.
I only had a few minutes to work on it when an e-mail message to you bounced back. It seems to be working better, although staying logged in seems to be a problem.