Piezo Wierdness

[NovaKaine]

Hi All.
I'm having a bit of a problem with my diy piezo triggers.
Simply put they won't trigger properly.
If I hold them bare between two fingers I get a proper signal, but if I tap them with a drumstick or try to put them under a pad they just wont trigger.
Anything that seems to break the contact stops the signal.
I've made drum triggers before and never had this issue.
I'm using the latest firmware update 20100402.
The only thing that seems to work is the black conductive semi rigid foam used to hold electronic components.
Which is odd because I can just touch the foam anywhere and I get a signal.
As an experiment I used a steel rod from a triangle set I own and it worked fine, plastic or wood not so fine.
Also it seems that vibration will not trigger a signal at all only if I physically touch the piezo or the foam pad.
I've tried 4 different brands of piezo and the effect still persists.
I've lowered the threshold and the gain to 0 and still it persists.
Any ideas or answers are much appreciated.

[dmitri]

All I can think of is that you don't have proper electrical contact either on a signal or ground wire.