I noticed (after a fresh nuke) that I stopped getting pinyin practice fairly quickly, despite being wrong pretty frequently. On the "vocab" tab, all P entries are marked to be 6 or 7 days out and ~75% learned, even ones I knew I got wrong.
I got to a point where I was just hitting "show" which turned the box red, and then clicking "next", but could there be some internal error going on that is marking them correct?