Just pulled my new mac pro out of the box replacing my old g5. I had my speakers plugged audio port in the back of my g5 and all worked fine. Now with the new mac pro, I'm getting nothing in the back port, yet all is well when plugged into the headphone jack on the front side. I've been searching some forums and Im reading im not the only one whose experienced this issue, yet no one has a fix. Anyone have any ideas?