Yamaha DTXpress/DTXplorer/DTXtreme

I'm having serious crosstalk problems on my DTXpress III snare pad.
I get both Open Rim Shots and Crossstick sounds in the center of the pad
This has just begun happening and I've made some small efforts at 
changing the "rejection" and "volume" parameters but it doesn't seem to 
help so I've done a factory reset and that doesn'y help either.

So I guess the question is: Does anyone know how I can fix this problem 
myself or do I need to get a new snare pad or what?

Any help is really appreciated!!

Thanks.