Man, completely forgot about this thread again. OK, this is embarrassing but I'll fess up to it. The card is fine. The problem, I *suspect*, is that once junior was born we moved our bedroom downstairs so the kids could each have their own room (it's a 3 bedroom house we had built in 1998). So the master bedroom that had been my study for almost 10 years become our bedroom, and my study got moved to the loft above the living room.
So what I suspect is happening is that the wife and kids are causing too many vibrations in the loft. After my last post I reseated the card and no more problems. Heck, I think I've done it several times since my last post to fix it, and every time no more anomalies on the screen.
Honestly, I think it's the wife. She's only 120-125lbs, but she's always driven her heels into the ground when she walks (she swears it's from tap dancing lessons as a kid). MSI says they test the boards that are RMA'd and the first two were bad, so I assumed it was another bad card from them.