Yamaha DTXpress/DTXplorer/DTXtreme

I cant get midi to work with my set. All midi is sending out and in 
but when i hit the pads there is no signal. something i missed or 
what? The activity in transportbar in cubase shows in signal all the 
time. I tried to jack in a Studiomaster midi analyser and it showed 
error when i hit the pads!

Thx in advance /Danne from Sweden