Just bought the 60XBR950, and am having the same issue, did you ever get any answers?
If anyone has a solution to this let me know. I am using Component cables and a Progressive scan Sony DVD player. I've tried watching reference quality movies (Finding Nemo, Star Wars and Lord of the Rings) and anytime there is quick movement from one side of the screen to the other, the picture breaks up, showing vertical lines that 'split' the image across the screen, similar to 'artifacting'. I have talked to Sears and Circuit City employees to see if there is a solution to this and I discovered that their in-store models (while playing DVD's) do the EXACT SAME THING. What's up with that?!