I probably don't know the correct terms to describe this: I have a finder window open, with list of Quicktime .mov files all shot by myself, have been viewed before successfully. Today, whenever I single click on a .mov file in the window (which shoud present a new column with movie preview in it...) The whole window snaps shut! No error message, nothing. Just snaps shut. HELP! I can't open most movies on my drive, but then one I did open won't work now or vice-versa.