I'd sure like to know why MicroSoft decided to change the file extensions in Office 2007! The files won't open for people who use the 2003 version when I email it. AND when I try to cut and paste a row in Exel from an new file to an old file, it won't work! This is such a pain, because that means I have to save the file in both versions to maintain my ability to transfer cell information, or if I need to send a .doc to someone! Why? Why? Why?