Okay, here's what's going on: For whatever reason, the games simply quit working on my laptop, stating that they couldn't find the Direct3D output for my video card. I double-checked the DirectX, which was current. I updated my video card drivers. And still, games aren't running, with the same Direct3D error. Checked the DVDs for any damage. There wasn't any.
What strikes me as particularly annoying is that the Sam & Max games are the only TellTale games that aren't working. I've pulled demos for SBCG4AP and ToMI, and they work just fine. So what the deuce is going on?