Why Now?? (Midi Issue)

Hi All!
 
I've been working with midi for a while now and I have two midi sources or modules that I use:
 
1) Yamaha MO8 Workstation
 
2) Kurzweil PC2R Sound Module
 
These two sources have been working for me for the past 4 or 5 years now with no issues.
 
Suddenly today I find out that with the Kurzweil (only) I can't patch more than one instrument sound regardless of the amount of tracks.
In other words, If I set up 2 midi tracks, first one with a piano patch and then the other with a drum patch, I only get the Drum Patch on both tracks.
 
I even started with a blank template and inserted 2 midi tracks, Bass on one and Piano on the other.
I insert the bass patch and it plays fine, then I insert the piano patch on the second track it plays fine, but when I go back to the bass track (yes I select it first and the "Input Echo: Auto Thru" button is lit) the bass track is playing the piano I patched in the previous track.
Switching back and forth at this point does nothing, just the piano patch is sounding on both tracks!!
 
I even reversed the insertion of patches Piano firdt and bass second, and whatever Patch I select "last" seems to overide the other tracks.
 
Does anyone know how or why (after 4-5 years) this would suddenly behave like this?
 
Any help would be appreciated.
 
 
Harpo
 
  

I'm stabbing a little in the dark here, as I am not familiar with the Kurzweil, but Yamaha synths typically have a "multi" mode that allows you to access more than one patch at a time.  When the synth is in "patch" mode, only one patch at a time can be accessed.  Is it possible that your synths got switched out of "multi" mode and into "patch" mode?  I don't know your synth specifically, but on my old Yamaha SY99 there is a key on the top panel that you press for "multi" mode, and another key for "patch" mode.  That's my best guess at this point.