Best vibration sensor for Spark?

I guess 337 days isn't too long to pick up a conversation...

I've been having great success with these sensors from MEAS and my Arduino, but am having a hell of a time getting things working on my Spark. At the moment, I'm pointing my finger at a problem reported by others whereby the analog pin is reading 1.7v as soon as analogRead starts running. I have read through the below thread and understand why this occurs on unconnected inputs. I don't understand why this sensor is behaving like its not connected. Or maybe I should say why the analog input doesn't seem to see the sensor. btw, I see its at approx 1.7v (aside from my DMM) because my adc readings for that pin jump right to 2048 on power up.

Thanks as always.