It's pretty much resolved, even though the cable folks have not been out yet...I traced all the wires to the attic, and it turns out my jack has some "issues". I loosened the cable and it's fine now...except that I'm now leaking signal.
So when the tech gets here, I'll point him at that cable jack...wait for him to investigate everything else, and then tell me "that jack needs to be replaced". If I can resist murdering the cable guy, I should be in business then.