If you're able to trace it back to the TV, and it does that with nothing connected, then I might inquire about an exchange. I've not seen this symptom posted about before, but it sounds like either a replacement or sending it in for repair.
I would greatly appreciate some help. I bought this TV (32" LCD) with a Panasonic blu-ray home theater system (Panasonic SC-BT230) and am in the process of figuring out connections. A problem we are having is that the screen flashes white intermittently. This started happening, FWIW, while I was working the "plug&play" menu, but has continued while we watch a movie. I thought it might be the cable, but it still happens when the cable is disconnected from the TV. About every 30-60 seconds, the image will flash to white (you can barely see "ghosts") for about 5 seconds, then back to image. I have not been able to find an answer.
(Not sure if important, but I also have a wireless USB plugged into the blu-ray player, but have not been successful connecting to our wireless router.)
Please help? Should I just return the TV and get another one?