Quick update - additional occurrence of a need to reboot...
Last night when I went to watch something on it, I selected the appropriate input on my TV and saw it was a black screen. I had sound, and pressing "Cancel" (as I do to quickly see the info banner) worked, showing the banner. I checked the TV1 modulated outputs on both Ch. 3 and Ch. 38 and they were also black screen with sound. I checked the TV2 modulated output and it too had the same symptom. I powered off both "sides" of the 222 and they both showed the usual bouncing logo. Powering on resulted in the same issue.
I did a soft reboot and that fixed the problem. I prefer to just leave my receivers on all the time (ensuring they are staying cool enough though), so this issue could likely be caused by that. I do have the updates enabled, however. Thus, it should be rebooting itself each morning.
Again, I'll keep everyone informed of anything else I happen to notice.