I have a Mac Pro 1st generation with 6Gb of Ram. The problem that I am experiencing is that I have no sound while using Apple Programs such as QuickTime. Quick Time will play my MPG videos but there is no audio. If I play the same videos using the VLC player they play perfectly with both video and audio. I can use iDVD to produce a DVD of my MPG or WMV movies but I obtain the same outcome with the resulting DVD having good video but not audio. The only apple OS X and iLife programs that have sound with it is iTunes and DVD player. If I install a DVD made with Wondershare DVD Creator the DVD player will play just fine and it has the audio. What do I have to do to get audio with QuickTime and iDVD?