Originally Posted by jeff1947
1) I cleaned and re-seated the digital audio coax (it's not really coax like I'm used to seeing [RF], looks like high end RCA type stuff) on both ends.
Digital audio really does need coaxial cable to operate well and this generally means a thick cable (~6mm) with RCA ends. You can also use a good quality TV antenna lead (the one with screw connectors) and use RCA connectors on the ends instead of the usual TV connectors.
However, if some titles work and others don't I would say the problem is some incompatibility between the specific titles themselves and your AVR. Hugo, I understand, caused a lot of playback issues due to the new DRM it uses although I don't think there were reports of audio issues per se.
Does your AVR support DD as well as DTS? Your comments so far seem to indicate only DTS.
The Oppo has the ability to transcode any soundtrack to DTS, for the coaxial audio output, via a menu option. You might want to engage this and also activate "Secondary Audio" as a test. I believe this will decode any soundtrack to LPCM and then re-encode it to standard DTS in the player. If there is an issue with the DTS being output from certain discs and your AVR, then this might correct it.
Of course, it would be better to update your AVR to take full advantage of the lossless soundtracks on Bluray titles. The AVR doesn't need to decode the lossless codecs: many older AVR with HDMI are capable of decoding multichannel LPCM even if they can't handle TrueHD or DTS-HD and the Oppo can decode any soundtrack to multichannel LPCM and output it via HDMI (effectively doing in the player what the AVR would do). However even the low end AVR now generally handle all lossless audio codecs: I'm just saying don't exclude older AVR with HDMI from consideration if you can get one dirt cheap.