Some questions:
1. Do you have a cable box and, if so, how is it connected to the display - direct or through a receiver? If it is directly connected via HDMI, did you try a different HDMI input? If directly connected via component video, does the display have a second set of comnponent inputs to test for the problem If using a receiver between the cable box (if you have one) and the display, are there different inputs to try the signal through to replicate the problem?
2. If you do have a box, did you replace it to see if the problem persisted?
3. How do you get Netflix -- through the TV, a blu ray player? If a blu ray player and there's no problem and depending upon how everything is connected, switch the blu ray player and cable box connections to see what happens.