Try de-activating and the re-activating your link between the player and Netflix's online service. This may do the trick.
I have a Samsung BD-P2500/2550 Blu-ray Player that streams movies directly from Netflix. Recently the audio has stopped working. I can watch a DVD on the Blu-ray with audio just fine, but when I stream a movie from Netflix directly, the video is there, but there is no audio. It's been like this for three days. I called Netflix directly and they have never heard of this issue, nor do they know how to fix it. Audio is set up for PCM. Can you please help? Thanks!