A FM11 file has a .fm extension and opens fine, but when I add it to a book FM shows the message "The file <name> is not in recognizable format". In the book, the file shows the M icon for MIF file. I'm sure I never saved it as MIF. I resaved it as .fm, then deleted and re-added it to the book, but it still shows the M icon in the book. What to do?