Tonight I noticed that the recording light on my 622 was on when it shouldn't have been. So I turned it on and found that it was recording a program that it should've recorded earlier in the evening. So I went to the recordings list and saw that it hadn't been recorded earlier, but several other programs that were NOT scheduled to be recorded had been. So I clicked the DVR button one more time to go to the recording schedule, and I found it filled with a large number of events that were all labeled No Info Available. One every hour on both tuners, in fact! Then I went to the guide, and I saw that all channels were showing No Info Available. Essentially, it appears that even though there wasn't even program titles any longer, the DVR was recording every program on the channels that I had had timers set for tonight! Obviously there was going to be a problem! I couldn't have both tuners recording continuously every hour or I would quickly run out of disc space. So I rebooted by holding down the power button. When it came back up, nothing had changed. I then tried pulling the power cord. When it came back up, nothing had changed! Finally I tried a check switch. This time, it took what seemed like much longer than the claimed 5 minutes to re-load the guide data. When it was finished, the guide was properly populated with all information again. However, it took several more minutes for the timer system to figure out that it no longer was supposed to record everything that it had previously scheduled to record. And even now, there are still a few programs in the recording schedule that are re-runs being recorded as new even though they do have the episode numbers and original air dates. I've seen that happen before, and usually it clears up as the time gets nearer. But I've never had the DVR decide to record everything because all the data has gone missing before! I wonder whether it would have fixed itself at the 3AM reboot, but I wasn't going to take any chances after two forced reboots failed to fix it. If the check switch hadn't cleared it up, I would've unplugged it and tried again in the morning when I could babysit it rather than risk having all my unprotected recordings deleted.