My tv is doing something that I haven't read about on any forum yet...it works fine for awhile and then the picture disappears (sometimes along with the audio). After a short period of time ( 10 seconds to 30 seconds) it will come back. Sometimes it'll be on for sevarl hours before it starts acting up, other times it'll be after a shorter period of time. Once it starts, its pretty consistent until the next day> I suspected the cable box but thats not it. Any ideas?????