Hmm...I suspected my comments would trigger more discussion about Bump Steer...and rightly so in my opinion.
I found the bump steer to be quite scary and I was never able to predict when it would occur as some obvious bumps didn't seem to affect the car, then something unseen would cause a violent kick to the steering. Certainly made me grip the steering wheel tightly with both hands, but I seemed to experience the effect less and less as the drive progressed and my confidence increased.
Is the bump steer effect less obvious when the car is being driven enthusiastically than when pottering around?