Yamaha DTXpress/DTXplorer/DTXtreme

hello all. I have a DTXTreme-2 and have a snare dropping out every 
second bar. Played a prom gig and only used 3 toms, kick and snare. 
Used acoustic hats and cymbals. 2 monitors, JBL EON and Yamaha 
keyboard amp. Had the JBL cranked. Contacted Yamaha and they think, 
1. pad, 2. cord, 3. module. Through headphones I cannot reproduce 
the problem. Turned the self reject and reject to it's lowest 
settings on the snare. Someone mentioned that the speaker could be 
causing my pizeo to "feedback" causing the note to cancel once in a 
while. When the snare doesn't trigger it's while doing a simple rock 
beat. I noticed the gain on my pad was turned all the way up so is 
it possable to overload the imput of the module? I turned the gain 
down (a little dial on the pad). Now the hardest hit on pad will 
bring it up to 95%. I hit the snare pad fairly hard live as it is 
rock (do use proper Moller Technique). Read all the postings on 
cross talk but thought I'd ask this question fresh and get your 
wisdom. could vibration of some sort cause the snare not to trigger? 
This one has got me stumped. The module is under warranty but hate 
to send it back if it's a setting or adjustment i could change to 
solve this. Could i be hitting the pad that the rim and snare are 
trying to trigger at the same time and somehow cancelling each 
other? Another thought is the compressor in the JBL is cutting in 
thus cutting out the snare note. Did have a problem with the JBL 
before but repaired under warranty. Back then my kick was cutting 
out when using an Alesis D-5. I do play the snare loud and the JBL 
is on the verge of distortion. Getting another monitor system and 
taking the JBL out of the loop. Any suggestions would be 
appreciated. When the snare drops out during rehersals or live this 
is fustrating to no end. I have no problems with the toms or kick, 
just the snare playing half notes. Thanks!