I typically watch TV from my computer, using the Xfinity website. Several times when I'm trying to watch auto racing (international events like F1 and WEC, don't care about NASCAR), the program will be listed on a certain channel, I click on it, and it's showing something completely different. I don't know why this always seems to happen with racing, but I assume it has something to do with the fact that they're international events.
Right now, I'm trying to watch the Qualifying session for Formula 1 in Australia. It's listed to start at 10:55pm on channel 174. Click to watch it, and it's showing some UFC fighting event. No matter how I try to search for it, I can't find Formula 1. So I'm missing the first Qualifying session of the season. Pretty awesome.