Ya know what, I might have been. I'm not sure if I had Rig Manager running at the time but the USB cable was definitely connected.
Yep...been there. It happened to me when I was setting up my initial performances after getting mine in the mail. Too much button pushing while it's connected via USB will crash you. I'm almost certain I've heard someone say on here 'Don't EVER EVER EVER have your KPA plugged into your computer for a live performance'. I actually got it tattooed on my arm to remind myself...and sho' 'nuff, never had a crash. Knock on wood.