There was a mistake in the text format upgrade in the question bank. The wrong conversions were performed, and the wrong arguments were passed to text_to_html in the conversions that were done.

Also, not all the calls to format_text had been updated to use the values in the new format columns.

I think this change fixes everything, but I have only had very limited time to test it. I am committing it anyway, because that seems to me to be the best way to maximise testing. I think that the new code is certainly better than the old code was.