I keep getting a little question mark appear on the screen momentarily, just before my G4 boots. It doesn't seem to stop anything from working, at least not so far. I recently installed some software which I understand can sometimes cause the system to do this. Should I be concerned? I've removed my ram chips one at a time and inserted in different slots which makes no difference, although I did get it to boot one time without the ? but I could not repeat it. Larry