You have to set Netflix to run with Silverlight. This is the procedure:
1) In Netflix go to the bottom.
2) Click on Help Center.
3) Then click on Internet Connection Speed Recommendations.
4) Then click on Video Quality.
5) I set mine to Medium
6) Finally, clear the box that reads, "Prefer HTML5 player instead of Silverlight."
7) Click the "X" in the upper right to end procedure.
8) The audio and video will now be in sync.