Just got off the phone with Judy at COX, and a technician will be here tomorrow morning to replace that noisily unhappy box. She did try rebooting it at her end, which stopped the clicking for a short while, but then it came back so now I've got the unit unplugged (at her suggestion - "just in case" it's getting ready to explode or catch on fire?)  

Judy did mention that we'll lose all of our recorded shows when the box is switched out, which would not usually be an issue... except it turned out that the show Aja wanted to watch at 7:00 last night wasn't actually airing here until 10:00 (when they'd be out with friends), so I taped it for her.  Which means she MUST watch it today before it disappears.  Of course I have no idea what her work schedule is, though I do know she is working today and won't be joining us for dinner.