no it was definitively not a code area.

I had this problem with the footnote in [emacs] perl info file and I didn't try to repair it.

Though now it magically disappeared...

As I said it occurs sometimes while updating or previewing a post, I'll check the header next time, maybe the CGI gets confused.

UPDATE: IIRC it also happened with € signs. And escaping to an HTML-Entity occurs with symbols like ⅛, but that's not the case here.