Swissman,
I tried the style you mentioned switching from VarA to B and that certainly shows the effect. It's due to the CyberPad which is a heavily sustained voice being switched from a low, barely discernible balance of 40 in VarA up to 100 immediately the VarB button is pressed.
It's particularly bad because even if you take your RH fingers off the KB before pressing B you still hear a residual effect because of the slow release of this voice. (As it happens you can eliminate the latter by taking the release negative in Voice Set).

No amount of explanation excuses it though. I'd be as interested as you in others' comments.
Presumably this happens with PSR 3000K used extensively on gigs also?

John

[This message has been edited by jwyvern (edited 07-15-2007).]