Yamaha DTXpress/DTXplorer/DTXtreme

greetings to all.im haveing the same old problems in live situ with 
snare cutting out in middle of fills or even just when playing time.i 
have played around with self rejec and rejec but still to no avail.it 
p-----d me off so mush that i took my accoustic kit out to a couple 
of bookings.if anyone can help PLEASE DO. of particular interest 
would be the self rejec settings you have found that have worked for 
you in a live situ.it just ruins your whole gig and whacks your 
confidence when you arent sure if the snare is gonna be there half 
way thru a s/stroke fill or something more complicated.ive paid a bit 
of money for this rig and dont want to have to get rid of it.on the 
positive side it records well.