I came across your website too late!
My Samsung HomeCinema Bluray Player HT-J4500 started giving error message 'FAN NG' and stopped working. The option was to return to factory. As an alternative I found a software upgrade online (B-JM63HTBWWB-1012.5). I upgraded my Blu ray player with USB and hey presto it started working again.
But as you guessed now I have a problem, possibly a Cinavia problem.
Certain Movie files do not play the speech audio. The background music plays correctly.While so many others play correctly. I have checked that these files do have proper audio by playing them directly through the TV(files stored in USB).
Is this a Cinavia problem or is it something I can sort out in settings?
If it is indeed Cinavia is there any way back or out of the update which I have already done?
Need some help desperately!

Thanks