It sounds like you're zooming an SD movie. Are you on the correct channel for the HD version of TCM?
I tuned to TCM to test your scenario. The image looks crisp and clean for classic movie standards. Mine too is not full screen. Perhaps TCM crops off specific cinema aspect-ratios to fit the screen top-to-bottom. I'm not familiar with this film to notice what would be cropped or missing from the sides of the set.
Your blurry video is what concerns me. If you only swapped out the cable box (Rovi to Contour), I'd suggest swapping the box again, but you've been since adjusting the TV settings. Review the setting on your TV again and disable any video processing, such as TruMotion or Real Cinema. Sometimes those "compensations" only blur or worsen the picture.
If you'd like, you could reset the TV to factory defaults. There are also lots of professional reviews of TV sets with recommended calibrated settings. Just search calibration settings with the make and model of your TV. Finding professional calibration recommendations is the first thing I do when researching TV sets.
If you provide the model of your LG, we could find a calibration for you. They're usually pretty good reads. However, I would caution, to actually do the calibration during the time of day when your concentration and patience is best.
