Hi Paul
in my case, the problem occurs even when I use simply the standalone application. Even when I click a key on the keyboard onscreen with my mouse (!) I can reproduce this. I think this is a strong case against the MIDI CC-theory.
Strangely, not all libraries seem to be affected. For example, the Big Bang Library works like it should, Synchron FX Strings and Synchronized Dimension Strings however are heavily affected. The free flute is the worst of all.
I am happy to help in your investigation, I am just a little short of spare time the coming days, sorry. (Wife has to do night shifts in the hospital and I have the kids around ... )
Best wishes
Michael