An Adobe Help Line colleague asked me to post this issue with LR 5.7. When importing RAW images from an external card reader(CF card being the original media) it imports them in random order when the sort toggle is clicked "file name". When photographs are first copied to the MAC HD this error does not take place. However, that's an extra step that should be avoided. Can you look into why CF cards on an external reader cannot be imported by file name?