I received the new magnets today, installed them, and I have success! Where as the first switch had to be almost touching to function, this one works just fine with about a 3/4 inch gap. I have a piece of mastic tape as a gasket between the door and the magnet, with no metal making any connections, per your suggestions.
I'm still not sure exactly what happened. If the old switch became weaker, or the door's magnetic field became stronger.
Or both.
If anyone requires a stronger magnetic switch, this was $11 something incl. shipping.
www.ace4parts.comAce Electronics
Houston, Tx