I was using a non-Apple keyboard at my computer (briefly in place of my wireless Apple keyboard), and I had temporarily switched the roles of the Command and Alt-Option keys so that I could do key commands normally. However, when I paired the wireless keyboard again and switched the profiles back, it still decided to have the two keys' roles swapped. Currently, on my Apple keyboard, I have to do 'Alt+Q' to close an application, even though I reset the modifier keys to default. This is puzzling. Any ideas? Thanks, -MDD.