The Yamaha AN1x Synthesizer mailing list

Today I had a strange and frustrating incident with my an1x.
I was working on a tune in Cubase sx2 and had a sysex data with the 
patch I was using in it. I loaded it today and the patch wasn't like 
the one I had before.  The name was correct, I would say the parameters 
was set close to that patch before but some parameters were completly 
changed, like feedback, lfo wave and speed and fiter mod depth - and 
overall sound was different.  I could say it was a version of the patch 
I might had on some time.  I thought I could have recorded that sysex 
in this particular file so I checked 10 or so versions of the tune's 
files, and I was amazed: all the patches was same as the changed patch 
but none had the patch I was using! I'm sure that most of them was 
using my patch without any changes made in every next file name.
Any ideas about what and why happened?! I'm pissed off a bit...