That's a pretty outdated site, and I'm looking into that.
As far as the current issue at hand, the best I can suggest is to have the unit serviced. If it's always done that, it probably should have been addressed immediately. If you're still under warranty, you could call 800-SAMSUNG and have it inspected; otherwise, they can still inspect it, but the cost will likely be out of pocket.
If you're in the U.S., register your product online, and you may be able to qualify for an additional 3 months of warranty coverage. You can do that here.
Since I got the set last year, Ive noticed on occasion, the background flicker when just the right mix of light to dark material is present on sreen. I have looked through all the information and settings, disabled all power saving features, tried to filter the incoming power the best I could with both a TrippLite UPS and a home theater power strip with noise filtering. It happens with all inputs, and all source material, 480i to 1080p, cable TV or gaming on PS3, component or HDMI.
Until recently, I had thought this was just a problem with ALL plasma TVs, but then I found this Samsung FAQ here
And it describes my problem exactly, only I notice it on far more content than just late night talk shows.
So my question is, is this normal? If not, what can I do to fix it?