I went around and around with Samsung tech support today via live chat. They had me reset my player and my Samsung TV to factory default settings. The HDMI bug was gone (in other words, after playing a disc, Netflix streamed videos now had normal sound). But when I changed the settings in my player to my usual settings, the problem returned.
In my system (is this true for others?), this problem occurs when the audio in the 6500 player is set to Bitstream (Audiophile). If this audio setting is left at the default setting of PCM, there is no audio problem when going back and forth between a DVD/BD and Netflix. So the workaround is to leave the player audio set to PCM.
Samsung says this can't be fixed in an upgrade--but I don't think that "Nicolas" or whatever his real name is, completely understood the problem, since he kept typing "Netflix app is not compatible with bitstream audio," which is simply false.
AT&T U-Verse Northeast Ohio
Denon x4000, Carver m1.0t, Samsung LED TV, B&W 704 mains, two M&K subwoofers, Oppo 103, Roku 2, etc.
Headphone system: Sennheiser HD600, AKG K701, Burson HA-160, Marantz CD5004, Denon DVD-3910