I'm sorry to hear you're having troubles and your frustration.
There are two possible solutions:
1. You can downoad the latest firmware update to see if that fixes the problem - often times, that will do the trick.
2. If your television is still under warranty, why not have a service tech come out and repair your unit?
I want you to be happy with your purchase, and I apologize for the inconveniences you are experiencing.
i am very frustrated with my Samsung series 6 650. the audio drops out and I constantly hear snap, crakling and popping noises (especially durring news programs and programming with a lot of dialogue). Samsung keeps telling me it's my cable box along with the excellent advice to unplug the set and my cable company keeps telling me it's my TV. I have already been through two motorola cable boxes and the problem persists leaving me to assume it's the Samsung TV I bought that is the problem. Samsung has been less than helpful and the store I puchased the set from in now in bankruptcy.