I recently started re-using some Logitech Z-4i's with my MacBook Pro... I used these speakers earlier in the year, and they worked well. I use them again, and they worked well. But now, after needing to go mobile for the first time since using my speakers again, I have discovered that I get NO SOUND from the INTERNAL SPEAKERS when I am not connecting out to my Logitech speakers. This is quite frustrating... I'm not even able to control the volume (its greyed out when not connected to the externals). When I unplug my line-out from my headphone jack, the headphone jack is glowing red, indicating that it probably still thinks something is plugged in there. I even try to restart the computer, and it makes the startup sound, and then the headphone jack glows again. Is there anyway that I can reset my sound card? Anything that I can do to fix this? Is this a common occurrence? HELP!