I have a strange issue happening with my Mitsubishi WS-55813. I have had the TV for about 4 months now. Every so often, twice that I can think of, my TV will just shut off for no apparent reason, while I was watching TV. After this has happened, the front green "Power" light flashes. During this time, I cannot turn the TV back on. The flashing light lasts for about a minute and then I can turn the set back on. Is this something that I should be concerned about?