I've received an replacement HD XL for my original one which had problems with the fan. The replacement Tivo works, records, and views shows, but also locks up. Twice now when I turned the TV on, the screen was pale gray. I had to power down & reboot each time. I've got OS 11.0K, that's the most recent I belive. My previous Tivo didn't have this issue. So either this OS is bad, or This tivo is flaky. Is anyone else having similar issues?