Comment form partially disappeared

In the past week, my comment form has disappeared in Firefox, not in IE. In IE, it asks for a name, email and website, then a space below for a comment. In FF it just has a big blank area where the name, email, address go, and then a spot to comment. when I leave just a comment it replies with
Error: please fill the required fields (name, email).

any thoughts? I did install backup buddy plugin about 3 weeks ago, but I believe that’s the latest plugin/update I’ve done.

thanks!

carrie