I have found that Denon DVD players cannot upscale to 1080P when you connect with any recent Samsung Full HD sets (mine is the 40N87 and I had the same troubles, except the player was the 1940).
I was suggested by Denon to change the picture setting to NTSC, which cures the judder but makes the picture blurred when using PAL disks.
Myself and another with the same problem posted a thread along the same vein in December/January and we got no joy on this, which suggests to me that this incompatibility issue (as far as I know the Denon works with other Full HD sets) has not been sorted yet.
I did not want to hang around for an solution to the problem (if there was one) and I reluctantly ditched the Denon for another upscaler.
I would suggest that you keep on pushing for a solution though before making such a decision.