Peter: I understand. It is clearly something new that has cropped up, since I did not make any setup changes either.

Mac: Thanks for the sugegstions. Tried it again; no luck. So far, ONLY using different sound output channels for BIAB and the standalone VSTi voices removes the hitch. Not critical for me at the moment, since my laptop setup cound card (Echo Indigo ASIO) will permit that. And of course I can run through Ensemble as well, and the hitch goes away.

I will continue fiddling. Tomorrow I'll install the 2009.5 upgrade on my desktop using identical VSTi voices with the M-Audio 24/96 and see how that goes.