there is major motion blur (pixelization) on fast changes/actions, live and off DVR.

I have a new Sony KDL-40XBR4, 120Hz with CineMotion on 1 and picture does not improve with Motion Enhance.
I did notice last nights HBO fight was particularly bad but todays NASCAR is very good. In fact I've seen no blur/pixelization with the NASCAR prodcast yet.

I'm new to judging HD quality so what is it that I'm actually seeing--what's happening at Comcast?
Dan