Ok, I power cycled the ceton one more time and it fixed the green screen video problems. Everything is coming in clear now.
It crashed on its way over to ESPN from Fox News when I typed in 1030 (not hitting enter after). So I had to reboot it again.
I still can't get recorded shows or movies to play. They still get stuck on loading.
EDIT: And switching back to Fox News crashed it again. That's too frequent to keep crashing on channel changes.
EDIT AGAIN: I guess it's not necessarily a complete crash, more like a lockup, as I can hit the WMC button and access the menu and move up and down, even access the guide. I can get back to live TV by selecting a channel in the guide but the way it flashed and paused and flashed again (within a second or two) before eventually getting there makes it feel very unstable, and I'm noticing some very frequent pixelation on AMC HD now. So I just power cycled again and it took me right to AMC HD and the pixelation is much less than it was but still there. It's the end of an old film (Princess Bride) and soon Hannibal will start, so I'm going to leave it on this channel and see if the pixelation continues.