Yes, I have to admit I've seen it in store. Settings are unknown. I do not mean that burn-in can happen during ten minutes of displaying the same image (or part of it), all I mean is it can happen. Do not believe all those PR promises that it is a problem of a past.
The same goes to phosphor trailing.
This certain TV set I'm talking about presents movie trailers all the day. Sometimes you can notice that there are "unwanted" horizontal lines on top and bottom of a screen when there is a movie with different aspect ratio than most of the other movies.
There is no doubt plasma has the best blacks, the best contrast, the lowest response time. All I'm saying is that burn-in and phospor trailing exist and I'm very sensitive to it, so I'm buying an LCD with worse parameters, but with more stable future perspective.