Poor sound from rental Blu-Ray discs

Hi all, I'm back to the 'Gon after an absence. I just bought a Samsung 55" LED LCD 3D TV and Samsung Blu-Ray 3D disc player. My pre-pro is a Sherwood Newcastle P-965 without HDMI. The Blu-Ray player only has HDMI out and coaxial digital audio out (no analog out) so I am using the coaxial audio out into the pre-pro.

Here's the problem. When I play a standard rental DVD from Netflix, the audio sounds fine, multi-channel surround like I am used to. When I play a purchased Blu-Ray 3D disc, the audio is also fine. When I play a rental Blu-Ray disc from Netflix, the audio sounds horrible -- like monaural, or possibly center channel only, going through 7 speakers. There is no background music or ambiance or sound effects -- the movie sounds eerily quiet except for dialog.

I went into the Samsung Blu-Ray player's audio menu and tried all the settings: outputting as PCM vs. bitstream unprocessed vs. bitstream re-processed into Dolby or DTS; multi-channel compatible vs. downmixed into stereo; and downsampling on (48 kHz) or off (96 kHz). The best results were bitstream unprocessed, multi-channel compatible, downsampling off, with the pre-pro set to "Auto" decoding. This works fine for standard DVD or purchased Blu-Ray, but as mentioned, rental Blu-Ray discs sound horrible, like they are monaural.

The Samsung dealer says that rental Blu-Ray discs from Netflix do not offer lossless audio, even through HDMI. Can anyone confirm this? Is that why the audio sounds so poor on rental Blu-Ray rental discs?

One final complicating factor is that my pre-pro has been having faults recently, so it is probably time to get a new HDMI 1.4 pre-pro anyway. But I would still like to know why the Blu-Ray rental discs sound so bad when the standard DVDs and purchased Blu-Rays discs sound fine.