It seems like several models of Samsung plasma have a bug in their "motionplus" feature with 50Hz material.

I have a PS58B850 and I see flickering and tearing of vertical edges in panning shots. This happens with the internal DVB-T tuner, external input via HDMI from a Panasonic HD recorder and PAL DVD's. I don't see any artifacts while watching Blu-ray at 24p or NTSC DVD's.

Apparently this is a known issue:

http://www.avforums.com/reviews/Samsung-PS50B560-Plasma-HDTV-Review.html

but Samsung either can't replicate the problem or they don't think those of us in 50Hz countries will notice. And I see it any time the camera pans - in fact the higher the resolution and the sharper the edges - the more they tear so TV3 is actually worse than PrimeTV.

The set has a demo mode for the motion interpolation and the picture isn't corrupted on the non interploated side which suggests that there must be some way to turn off the interpolation feature even if it isn't exposed in the menus.

I contacted Samsung locally and the conversation went something like this:

me: Hi, I want to find a way to turn off motionplus on my expensive new plasma TV
samsung: plasmas don't have motionplus
me:  yes they do - it's written on the box

samsung: You can turn it off in "picture options"
me:     you can on an LED set but not on a plasma.

samsung: try turning off film mode
me:    film mode isn't available because I'm inputting 1080p

samsung: can you try 1080i
me: already have - and it's still broken

samsung: try turning off cinema smooth
me:    cinema smooth is only available at 24p

If anyone is interested and has a newish Samsung plasma I can post a short divx of some scrolling text which breaks up pretty severly - and I've been compiling a  collection of clips recorded off air which are particularly bad.

On the plus side - the picture looks amazing from 24p blu-rays or PS3 at 60Hz.