Dave Smith Instruments SYNTHESIZERS

Has anyone else experienced this? I have a very complicated 
sounding patch that I've been using for the last two months and 
I've noticed over time that it seems to have changed over time. I 
have a recording of when I first started using it and I have the 
patch stored on the computer so it's exactly the same settings as 
they've always had. It's just that it seems to sound a little different 
now.

steve