Essie, when I tried to change it last night, I just opened the file and tried to change it and nothing happened. This morning when I searched for it again, I right-clicked on "edit" instead (as well as changed the number to 500), and it worked fine for me. I don't know if what made the difference was editing it instead of just opening it, but try it and see if that helps. Thanks to all those who've replied and helped me out!