I'm sorry to hear that you're having this problem.
The best answer would likely come from a technician. I would recommend having service check out your set.
I have a 6mth old 40in LCD and the last week it has started to freeze on a channel and then lose sound, not respond to remote then shutoff with a loud click, after it reboots it shows the TV channel OK for around 20seconds then freezes again and repeats the whole process.
It started on 1 channel at first but now it appears to be creeping into all of the digital channels. Still covered by warrantee but looking for answers.