I believe that this may have been mentioned before but I thought that I would add it again in case the original post has been lost. This is extremely important regarding these displays so please read!
The current line of Samsung DLP displays will produce one of the most stunning pictures currently available once calibrated and with a high quality signal. But it is not without its set of idiosyncrasies. DNIe (floating black, excessive edge enhancement, horizontal banding) will occasional toggle itself back on - even if the user menu says it's off! We have found this to be the case when powering the set on, switching inputs, and/or scan rates. The easiest way to tell would be if the picture lacks any type of shadow detail. For a more precise analysis, one can toggle between the Low APL and High APL PLUGE patterns on DVE (T.12, CH.2-3). If the vertical strips cannot be seen after it's been calibrated - chances are that DNIe has turned itself back on.
We suggest the following procedure to ensure that it remains off for critical viewing. This should be done after you settle down to whatever it is you will be viewing (after switching inputs, channels, etc.).
1. Go to the user-menu of your display and toggle DNIe back off whether or not it is in the on or off position.
2. Then, enter the picture menu and bring brightness up one click from where you had it and then back down to its original position.