It seems to be using Silverlight for streaming videos, so you try to download such movies and save recorded Netflix movies to your hard drive using
Replay Media Catcher 4.
If you have a stable internet connection and doesn't experience buffering when watching Netflix videos, just record them from screen using a
screen recorder like
Replay Video Capture. It will allow you to record right using MPEG-2 video codec, so you won't need to convert anything after downloading.