Sorry - trying to find the right area to post. Last two months Comcast is dropping HD channels at random. Couple days later, the channels reappear. Comcast claims we cant get HD on our TIVO Premier Elite with M-card. - yet we have been getting it all year. I'm wondering if Comcast in North GA. is now trying to use SDV - and we dont have a tuning adaptor or box of any kind. The dropped channels are still available in SD. Sometimes the DVR diag. screen shows signal levels at 93 - and other values also OK - yet screen is blank. Other times, DVR diag. show blank values and Current Tuning State = Not Tuned: Wrong Card State. No one at Comcast seems to know anything at all. Again, could it be Comcast is now trying to use SDV in North Georgia. Anyone know?