Disappearing digital

I was visiting someone who has one of those new digital-ready TVs and an antenna the other day. I couldn’t help checking out the DT channels, and I made a discovery: There’s no fuzz, but the picture keeps blacking out; it’s just for a few seconds, but it keeps going. I went back to the old analog version of the channel, and I saw no interference with its signal at all. Since I can watch fuzz, but can’t watch nothing, I wasn’t impressed.