Check out this:
MIDI Troubleshooting 101
It sounds like you have the output of the MIDI track routed to the Windows Wavetable synth. You don't want this. Only route it to the specific VSTi you want to trigger with your edrum kit. In my case, I route the output of the MIDI track toToontrack Superior Drummer 2.0 or Steven Slate drum samples in Kontakt 2.
Brandon