I had exactly the same issue. Craft goes into an uncontrollable tumble at approx. 5km up, meaning a serious case of lithobraking! Happens on mun and minmus, haven't tried other bodies yet.
I also had it happen to me on take off, did you see this too?
I have KJR installed too, but with some further testing today I can't seem to replicate the issue. Have you guys got anything further?
EDIT: on testing another lander on minmus, the tumble happened on take off but not landing