The issue with the SD ch's is due to the compression ratios they use. They switched to higher comp ratios to accommodate more HD ch's. The converters in the SA set-tops are of mediocre quality hence the ever declining quality of the SD ch's. But that is not to say that there is not a finger to point at the TV's themselves. A good test is to screw the COAX out of the 4250 in to your LCD, check some SD programming. Then if you have one at your disposal hook a CRT to the 4250 via COAX and you will see how much is your TV and how much is CABLEVISION.