The Yamaha AN1x Synthesizer mailing list

Sorry if this has been done before, but I don't think I found it my 
title search.  I'm somewhat new to MIDI, so forgive any blatant 
ignorance.  I had the AN1x working w/ the editor software (which is 
very nice, indeed!)  I am trying to integrate disk based recording
now 
w/ same competer and have my computer sending MTC and clock to my 
keys, etc.  Coming out of my XO-60 into AN1x, the clock and sequence 
messages track, but I can't send the patch info. That is, the cable 
out of the computer directly into the AN1x works fine; pass it into
XP 
first and out of "through" and I get "Sysex error" sometimes,
"illegal 
data" sometimes, a never ending "recieving bulk" sometimes, and on 
still others, nothing.  Curiously (to me, at least), *sometimes* 
simply pushing "yes" on AN1x clears the above messages, and the 
requested patch is up and ready to run.  Most often, however, it 
sounds like a template/init patch has been loaded. And if I go
through 
a MIDI man 1-in/4-out thru box w/out the XP there at all, the same 
problem occurs.  Certainly I'm missing something re: the kind of 
messages MIDI can send or something?  Yet at the same time, there
must 
have a way in which you can have benefits of the editor and the AN1x 
further along in the MIDI chain w/out having to do cable swapping?  
Thanks muchos to all and any who can help shed light/solve.