anyone could help me with the dvd playback problem on G5(i don't know if this problem only shows up on G5s)?? i inserted a dvd disc, and the dvd player shows up with no sound at all!! and after that i checked the Sound preference in the System Preferences panel, the output setting was changed to Built-in Audioigital Out instead of the correct setting: Built-in Audio:Line Out. And, the setting was grey that i can't even change it back to normal... And the whole system was muted... The only way to resolve this problem is restarting the machine. i've tried several times but the problem stills, and i've searched all over the web(via google) with no result. Thanks everyone in advance....!!