DVD copy issue

[Muse]

I copied a DVD last night, a dual layer disk with about 5.3 GB data. I figured I'd run DVD Shrink on it. DVDShrink 3.2 reported it could do 75% compression and have both the LPCM Stereo and the AC3 5.1 audio (both checked). If I unchecked the LPCM Stereo checkbox, keeping the AC3 5.1, it showed 100%. I don't know, but I figured "what's wrong with AC3 5.1? So, I uncheck the LPCM Stereo and make the DVD-R+. When I play the disk in my computer I hear the music but not the voice during an interview. But when I play the disk in my Philips DVP642 DVD standalone DVD player, I hear both. These are independent of whether I select PCM Stereo or Dolby 5.1 in the Audio Selection portion of the disks menu. My PC audio is with my GTXP soundcard, using S/PDIF to my receiver. The original disk plays _both_ tracks OK in my PC, assuming there are dual tracks, which is apparently the case. Does anyone have any idea what's up with this?