What have you done in the TV's menu? There is a menu setting that allows you to choose a variety for screen formats as the default. I would need to look in my Sony manual to tell you exactly what that is (I'm at work now), but the setting tells the TV to either keep a 4:3 format on regular channels or to keep it in one of the wide modes. On my Sony, I personally keep the TV in the mode you have yours because the TV will display the correct format based on the signal it receives. Thus, when I watch HD channels (16:9) the TV will show this image correctly. If it is set to default to a wide mode it will incorrectly stretch the 16:9 image (basically doing a double-stretch).
My tv defaults at the normal screen size, where the image is centered in the middle, and there are black bars on the side, as to not skew the image. but i'd like it if the image was permanently set to "widescreen" mode, which can be easily changed by just going into the menu, or hitting the "wide" button on the remote. But when i change the channel, or turn the tv off, or basically do anything, it defaults back to its original, centered screen mode.
Is there anyway to fix this so my tv will STAY in widescreen mode regardless?