My Acer TravelMate 5720 has a new "problem." It has good audio via the headphone jack/line out, but no sound from loudspeaker. Further, when the headphones are removed from the jack, the loudspeker icon shows a red "X" and a "mouse-over" says "No Audio Output Device Installed". Similarly on Device Manager no loudspeaker is available. How do I get the Loudspeaker Icon, etc. back to normal and connected in the system. Thanks!