Hi Skip,
Just to refresh, I've had a gear retraction failure 4 times now and each time it was on very bumpy runways. Each time, it eventually does come up.
After we cleaned, lubed, and adjusted the emergency gear lever all seemed good for a few months. I then found another bumpy runway yesterday and the gear didn't retract. The override doesn't do anything so I would assume it's not the airspeed sensor. I would guess that microswitch, mentioned above, could bounce to a closed position, and then release to its open position a little later, allowing the gear to retract. That make sense to you?
Sonny