Greetings John,
Happy happy

I'm going back to Edmonton on the weekend to touch up a client's Panny 53" since he changed DVD units from an entry level Samsung to a mid scale Pioneer.
The Pioneer gives him a distinct green tint in the image ... so it is time optimize his TV for the new player. Until I return, he will continue to use the original player ... given the TV set up.
Just empirical evidence that TV's need to be optimized to the players.
This is not to say that signal generators serve no purpose ... because they do. They are great for roughing in a grayscale and other settings, but the ultimate fine tuning must be done with the DVD player.
I'm always warning my clients that want HD calibrated to bear in mind that the calibrated image with the generator might be incompatible with the actual material. More often than naught, the image is too dark after using the signal generator. Black detail is crushed ... on actual material.
Those that ignore the warning will usually tell me "it's too dark" after the HD calibration. Precisely what I told them it would be. So you get paid to say "I told you so."

There is also a general calibration rule of thumb for black levels. If you have to err, do it on the side of being bright rather than too dark. There are two black level patterns that one should be looking at ...
Regards