You know, this lack of preference for "auto-save" is much more dramatically bad than you would think. For example, I inserted SD card to look at pictures in Preview (sn: IPhoto, No, thanks!). I had turned off auto-save under Time Machine/Options. At first, Preview did what I wanted--specifically, it allowed me to review pics, rotate them, etc. without yelling at me to unlock the file each time I flipped a pic right, or whatnot. This way, I can go back later, after adjusting all the pics I took, and look at them all again, figure out which ones I want to keep and save them. I was interrupted so I quit out of Preview and--FRANKLY UNBELIEVABLE--the program wrote those changes to my SD card with no dialog box, no warning "how-do-you do", nada! That is a horrible, disastrous flaw. I do NOT want Apple to tell me I have to save intermediate versions unless I tell a program I want to, especially when external media are involved, but really any time. No problems if the default behavior is versioning but the user should ALWAYS ALWAYS ALWAYS have a choice of what to save, what not to save, to quit and save or to quit and not save. Sheesh.