I don't have any opf files in the same directory. Just the epub files.
The strange thing is that if language is set to Spanish then Calibre reverse the "last name, first name" fields orders and omits the comma. Another option is that maybe Sigil is doing a lousy job editing the fields. Is there any way to check the fields in the epub without using Calibre or Sigil?
I will give a shot with the regular expressions thing. But first I need to read the manual
