Just saw this last night... Man is this a beautiful movie! I have no idea why people would bring it down to "a good Disney movie but not for PIXAR standards," I thought it was and is awesome, a lot of fun! The 3D is great and the imagery is perfect. It still surprises me how I forget I'm watching a CGI animated movie with PIXAR. A must-have all the way!
Re the sound glitch, my 3D disc did do that in Dolby TrueHD 7.1 near the beginning, a bit of trouble visually as well. I rewinded and it played back fine the second time, no problems after that. My BD player is an LG cheapo one, and it has given me problems with some movies, so I no longer pay too much attention to it since I thought that would get fixed with higher-end gear which I would not get until my current one dies on me. An example of a 3D movie with a similar problem is Kung Fu Panda 2, also at the beginning. I found that by pausing the movie right when it's starting and giving it time (to buffer content?)---maybe 2 minutes---helps and most of the time fixes this.
This movie has TrueHD 7.1, TrueHD 5.1, a 2.0 track with enhanced sound characteristics, French 7.1 (TrueHD also?) and 5.1, Spanish 5.1. Maybe all this makes BD players sweat more than usual? And that's just speaking of sound, the quality of video on this one has to be more demanding to reproduce(?).
Speaking of sound, that D-TrueHD 7-1 track is bliss!