A few weeks ago I bought a Panny TX32-LX500 LCD TV and I'm very pleased with both the picture and sound. However, there is one thing that annoys me and that is that there's a rather hight pitched humming sound coming out of the back of the TV. It's not that loud and only audible when the volume is low or during quiet parts of a movie. Have other owners of the TX32-LX500/TX26-LX500 had the same problem? What about other brands/models? Do they all make some kind of noise?