So, I got up this morning at 7:30, in case Comcast was to arrive at 8 am (they said between 8 and 11). I received a call from the Comcast rep saying he was in route at 8:40 and would arrive in 20-25 minutes. He showed up just after 9 and he turned into them, because there were two guys. The had me show them where the cable came in and checked the lines. I explained the problem and the guy said it sounded like a bad box. They said the signal was low. They went downstairs and replaced an old connector in the box, which corrected the signal problem.
The guy was honest and told me he really expects it is a bad box and that he doesn't expect the stronger signal to correct the problem as I wasn't having a problem with a digital channel. I asked if they'd had a lot of problems with the dual-tuner box and they acknowledged that they were. I told him about the many complaints I've read online about the boxes freezing. The rep explained that they are out of boxes, because they've been replacing so many. He gave me his cell number and told me to check in with him on Wednesday. He said if they got some in, he would set a new box aside for me until next Saturday when he would install it.
All in all, the service was excellent. Sadly, my problem is not fixed, which makes me wonder if I'm going to have more problems with 24 this Monday. I hope not.