Content Block interface not quite right

Permalink
I am fairly new to C5. I am following the Basic Theme Development series, specifically #2 (http://www.youtube.com/watch?feature=player_embedded&v=9duLSgK21F4). Everything is going well, except that my Content Block UI doesn't have Cancel or Add buttons. Every other content type does, so I'm unable to add a Content block type. I have wrapped everything in the body of my default.php file in a div with id="hcc_theme" and pre-pended all my css elements with that id (#hcc_theme ). Still no buttons on the Content Block interface.

I am loathe to start mucking with the concrete css or php files, but this is a critical content type, and it ought to work, no?

Has anyone else faced this? Or better yet, solved it? Thanks in advance!

PS. The Cancel and Add buttons seem to flash when I first load the interface, then disappear. It's almost as though they're hidden behind the content area, below the rich content toolbar.