Update on this one: I just opened a ticket with the Outlaws, but figured I'd keep you guys posted. Here's what I sent them, so the backstory is all in one place:
Previously my PC's DVI out went directly to my TV with a DVI<->HDMI cable. This worked fine for several years.
When I installed the 990, I decided to use the Outlaw's video switching to make my life a little easier. So now the PC connects to the 990 with a DVI cable, and the 990 connects to my TV with the same DVI<->HDMI cable as before.
For a while, it worked most of the time. Occasionally when I first accessed that HDMI input on my TV and switched the 990 to the correct input, I would get no video. If I power cycled the 990, the video would appear.
Now, whenever I first switch over to the PC input I get the black screen, but power cycling the 990 does NOT work. I have to reboot the PC - which I know has not locked up, because I can use the Windows Key->t->r to reboot; i.e. I don't have to power cycle the PC.
The only difference I'm aware of is that I finally figured out how to get a true 720p signal to come out of the PC, which I would hope should make things better, not worse. I'm going to go back to the old screen resolution and see if that helps, but it's a less than optimal solution.
The PC is always left on.
-Joe