Hi, I have a similar problem with Premiere Pro (1.5).
I captured the footage with a Sony VX2000, using an XLR adapter that sent the audio to only one channel. I can hear the sound when I scrub through the timeline, but not when I play the project.
I think I encountered this long ago, with Premiere 6.0, and it was a switch or setting I had inadvertently changed.
Any ideas?
Thanks!