This has just started to happen to me also. I have to go in and reset favorites every other day because at least 10 channels just drop off. I have no idea what is going on, but it is EXTREMELY annoying. When this happens, even if I press the "Guide" button, the same channels will not show up. I have not idea why this just started happening and how to fix it. The only way to get to the channel is to press the numbers, but there is NO way to see the channel unless I go reset favorites. It is ridiculous.