Welcome to the forum.
The television panel itself is a 120hz panel, and it should be understood that regardless of the picture being fed into the television, it will always display at 120Hz. There will also be some signals being sent at different resolutions, such as 480, 720p and 1080i/p. Since the panel is a 1080p panel, the picture will also be upgraded to a 1080p picture, regardless of the source.
What you're seeing in the INFO bar are the Hz-ratings that are being sent to the television. Most sources will generally send a 60Hz signal, some will send a 24Hz signal, but all of them will be upconverted inside of the television to 120Hz. This is done by internal processing inside of the television.
Hope that helps explain. Does that answer your question?
Just bought the LCD 52" 630 series, love the TV! During setup I set the TV for 120 hz but notice when I change channels it indicates that it is 60 hz. Could it be our Direct TV box? We are waiting for the HD conversion later this week. Any experts out there? Appreciate any help!