I think the lack of consensus on the Rambo dropouts comes from the fact that people are using all sorts of audio connections, and it appears that this issue may only effect certain specific outputs on the 5K. Also, the early reports of this issue did not specify that Audiophile mode was necessary for it to happen, so the early testers may have been using re-encode mode without mentioning it.
The factors that I believe are important to the audio dropout issues are:
1) spdif output (optical in my case.)
2) 5K is set to Audiophile mode and NOT re-encode. (When I set the 5K to re-encode, the dropouts do not occur at the spots listed.)
3) The dropouts occurred at various places throughout the film, but the ones I listed for testing are during Chapter 2 at 8:17, and then again right away at 8:25.
For the video, I'm using HDMI (to DVI), and the TV is NOT 24fps capable, so it's 1080i. The scene that showed the odd "stuttery" video was Chapter 8, from 43:52 to 44:13 (as the team walks up to and through the cave.) As soon as the next scene starts (shot of plants in water) the issue no longer occurs.
The menu glitch occurred when bonus view was on -- while it was on, when I would pull up the menu to change chapters, the words "Chapter Selection," as well as the little chapter stills, were missing. If I navigated around a bit the text and stills would return.
Thanks for testing this if you get a chance.