Yamaha DTXpress/DTXplorer/DTXtreme

I have read of all of the problems with the PCY150s.  When I first received mine, neither the 
bell or the edge worked correctly.  After some fooling around with the inner workings, I have 
been able to get the edge working correctly, however, I'm not so sure about the bell.  It 
seems the area that triggers is very small- perhaps a half dollar sized area on the front of the 
bell.  The rest of the bell is unresponsive unless I literally hammer it.  Is this the way the 
cymbal ususally works?  Is there some type of sensitivity adjusment I need to make? I am 
using the cymbal with a DTXPRESS II kit.