I just replaced my 8-9 yr. old 17' Nokia with the 19" Samsung 997DF.
On the Nokia I had a horizontal black line near the bottom of the display that popped up every now and again. As time went on more lines came, more frequently, moved up/down wildly and then the top and bottom would randomly "twitch" for a few seconds (similar to a degauss but in a specific line)
Now with my 997DF, I'm experiencing a similar "twitch" but not in a line. It's on either edge of the screen, lasts for no more than a second, and mirrors each other. Meaning it's as if it's in a line, but the middle doesn't tweak out too.
This happens maybe once every hour and never in games. And it doesn't progressively get worse as I use the monitor (unlike my old Nokia's problem).
I moved the electronics right next to the monitor (wireless mouse receiver, cable modem, XM radio) and that did nothing.
I'm also running at 1280x1024@85Hz but that's normal. Color temp is 6500k but that's normal too.
I know the monitor could be defective, but would it make sense for such a defect to occur only randomly? I understand the monitor randomly going nuts as it fails over time, but to have a random oddity out of the box?
If simmilar things are happening with both screens it must be something else. If possible try a different video card. I seem to remember some settings in ATI drivers for + and - interlacing under the display settings. You might as well mess with those a little. If there arn't any electronic devices or other things that might cause EMI I really don't know what it could be other than the video card.