Just installed a 721 last night and things are kinda working. I can tune into a channel ok, but switching channels doesn't seem to work very well. For example, I fire up FoxNews and see O'Reilly's happy face staring at me. I watch for a few minutes, then key in 191 to switch over to TechTV. I get a black screen. I can't even switch back to Fox every time, though on occasion it will allow me to switch back. The only way for me to get TechTV on screen is to tune it to 191, power the unit off and back on. It will power up tuned to that channel and the picture is fine. I can then switch to Fox if I like, but cannot switch back to TechTV. On the other hand, if I'm on Fox and push the channel up button I can switch up to MSNBC and then switch back to Fox. I can continue to switch between these two channels without problems. However, if I try to switch between Fox and Court (which happens to be the channel underneath Fox in the listings) I get nothing again, just a black screen. I can get HBO by doing the power off trick, but not by directly tuning to it. It's all very strange. The software has been updated on the 721 of course, the switch passes its test without a problem, and my signal strength is fine. This isn't a new Dish install, just a new receiver. I was hoping the problem might go away overnight, but it didn't. I had it set to record Extended Play from TechTV at 10 this morning, and that failed. It didn't record 30 minutes of a blank screen, it just didn't record. The menu said something like "the program record failed". So, it knows it's getting a blank screen at least. This is starting to sound like a DOA unit. Just my luck considering how hard it was to get this thing.