I am still having this problem, but believe it or not the first reply was the most helpful. Whenever the speedo fails, a light tap on the right stalk (windshield spritzer, etc.) solves the problem. Sometimes its one tap, sometimes quite a few, but it has worked to far. A buddy who is a car repair enthusiast but no a Suby owner thinks that there is a switch module under the dash that might need some contact cleaned. maybe we'll work on it come spring -- right now a long way away.
Again, thanks for your help.