I had a little incident myself at my show last night, I think it was BA related. BA enabled but not visualization, As the playlist song finished BA kicked in and at the same time I pressed an instabutton "Cheering", a terrible screeching sound came out of the speakers,
I had to immediately turn volume on my mixer to zero. pressed the off button on BA turned volume back up and all seemed normal, pressed play for next singer Cue came up and stayed there, couldn't seem to do anything else so x out of Hoster and restarted the rest of the evening was OK but I didn't use the same insta button again. Have not Been able to duplicate it at home.
One difference in my home testing is I only have the on board Sound card, at my show I use both on board and usb sound card, whether this has any bearing on it I doubt as all the sounds were still routed through the on board card. I only use the USB sound for recording software.
Roy.