Patches and discussion for Ensoniq VFX family

Hi,

I went to rehearsal last nite and my SD-1 started going out of 
tune.  I checked the tune parameters under the MASTER button and it 
was set to 0.  It would go up and down in tune and then settle in at 
a 1/2 step low (play an E and it would sound like and Eb)

I opened the top cover today, and disconnected the power ribbon 
cable that plugs into the left most circuit board, just for the odd 
chance that it was dirty.

It has been stable for a few hours now, but I have a gig coming up 
in a few weeks and im worried it will act up again.

Anyone see this problem?  Any fix?  could it have been dirty power 
at the rehearsal? At home it seems ok again...

Thanks
Rich