Yamaha DTXpress/DTXplorer/DTXtreme

Hi, I am new to this group and was wondering if any of you could help 
me out with a problem I have been having with my DTXpress. I have 
conencted it to my P.C using midi leads and can exchange drum kits 
using DTXchange fine. I have started messing around with Cakewalk but 
have had a few problems. When I record from the drum kit onto a track 
in Cakewalk all the correct notes appear (i.e the floor tom appears 
on the coreect stave position) apart from the bass drum and snare. 
These appear on the same position on the stave (a position which i 
think is a default if the note is not recognised or something). When 
I play back my recording with the drum kit still connected it plays 
fine (with correct snare and bass sounds) but when the drum kit is 
disconnected all the notes apart from the bass and drum are still the 
right ones (although they are obviously the lame P.C midi sounds) 
apart from the bass and snare which come out as woodblocks or 
something like that.

Another question is is there any easy way to transfer midi files from 
P.C to the drum brain. The only way I can do it is to play them on 
the P.C and record them onto the brain at the same time. The problem 
is that using this method all the different tracks are given the same 
sound (piano) and so although all hte notes are correct, they all 
have the same sound (as opposed to some on bass, some on guitar etc 
as it shows and sounds in Cakewalk)

any help would be grately appreciated

Robin