I have a USB keyboard connection (AXIOM 61, not the PRO). I don't think it happens only when a VST GUI is open and in focus. A couple things for sure that always happen before this happens.
1) I have done quite a lot of editing using the PRV
2) As soon as I save the project, the problem goes away for awhile (which does support was Dan was saying). Perhaps the SAVE forces the SONAR GUI to be in focus and not a VSTi?
Thanks for the feedback.
Jim