Yamaha DTXpress/DTXplorer/DTXtreme

I have the following problems on my dtxpress1:

Hitting tom3 causes cymbal3 (I have a 3rd stereocymbal) to sound many 
a time (I suppose this is what you would call "crosstalk"?). Note: 
tom3 and cymbal3  do not sound together, it is or tom3 or cymbal3 
that is triggered by the hit. I tried something with rejection, but 
it didn't work, probably I did something wrong.

Another problem: the rim on my stereo cymbal doesn't work as I would 
have it: if a play a quick figure on it, many of the hits are choked. 
Changing the "gain" doesn't work here.