I have v3.3.6 of Advanced Custom Fields installed, and only one field group. When I go to the edit post screen, I get two sections for that field group, with nearly the same fields in them both. Putting data into one field group only partially works. I have to put some of the data in the other group in order for all fields to work. This seems like a bug. Any ideas why I'd be seeing the group twice in the edit screen?