Yamaha DTXpress/DTXplorer/DTXtreme

I'm glad I found this wonderfull group. I recently purchased at 
dtxpressII after playing on Whitehall double bass set for the last 
thirty years, believe it or not. So this is kind of a change in 
scenery for me. It's especially strange hearing yourself coming out 
of speakers 10 feet away, but anyway. I have a couple questions.

1). The Hi Hat pedal seems to work inconsistantly. The open and 
splash effect don't always work. Any suggestions?
2). The manual says there are 128 keyboard sounds available. I have 
been unable to determine how to access these sounds. Is it possible 
or, is this a midi function? 

perry