Yamaha DTXpress/DTXplorer/DTXtreme

hi. i've hooked up the dtxpress II module to my malletKAT and i can only get the GM midi 
sounds out of it. i want to play the pad sounds on the kat. i've tried changing midi 
channels, midi note #'s (c1-c5), pc's, etc. but to no avail. my patience has worn thin and 
i'm in danger of hooking my PTX8 back up!!! i hope you can help. 
thankyou,

parebele