Hi Mike,
If i put the unit back together with different glue, silver paint say, it has the same mass as the original unit, but the capacitance stays at 0.2nF. The only variable seems to be the glue. Also these are static values, measurements taken away from resonance so there isn't much vibration/motion.
That link is very interesting. I am reading it right now. It seems to say as the capacitance has changed the resonant frequency of the unit has also changed. Which would explain why it doesn't work any more!
Thanks,
Antknee.