Well, i have tried all the above mentioned options with no luck
I believe the problem is what Chris mentioned about the Bandwidth being too large in Blu Ray Discs. We tested Casino Royale in SD DVD with the audio set to bitrate and no problems.
The Blu-Ray Disc we have tried are: Batman Dark Knight, Celine Dion live from Vegas, Wanted, and Hancock. All disc have caused the in and out audio problems.
In order for us to watch Dark Knight this afternoon without any audio intermittence we had to change the Bitrate to PCM and watch the movie in Dolby Pro Logic (ugh).
So in order for us to get the best out of Dolby Pro Logic (until my dad gets a new preamp) what are my best setup options? I did change the downmix to surround encoded but not sure if this helped with Dolby Pro Logic.
Dynamic Range: Off or On?
PCM Down Conversion: Off or On?
Downmix: Stereo or Surround Encoded?
BD-Video Secondary Audio, Off or On?
thanks to everyone who contributed!
I will return to this website in the future before buying future equipment to help support.