Arduino + sparkfun Mp3 trigger *Help Required *

I have used Piezo sensors as analog inputs into the Arduino. Digital pins are set HIGH but trigger LOW once the piezo is deformed. The program has been tested and is working well with LEDs attached to the digital out puts.

However when i attach the digital outputs to the sparkfun MP3 trigger it will not trigger the sounds. It will only trigger if one output is connected, if any more than one is connected it will not trigger the sounds.

I have ensured all the tracks are allocated to the correct trigger inputs.

Can any help?

Thanks a lot