Sorry for spamming guys... Issue solved by my own during a lunch time...
TV has a factory setting of 'Motion plus' set to Standard. I had to switch it to "Pure" (don't know term for English language Tvs). There is also option "Smooth" (scene still distorted), Demo, Manual and Off. Wondering what first two are useful for. Hardly imagine I'll change it from "Pure" ever, because other settings is causing also digital Tv signal to be distorted.
Hope my folly helps others
Just bought a new Samsung 2011 46' LED 3D Tv 6 series (Europe model UE46D6530). When playing ALL my .mkv rips (stored through 100 Mb/s LAN or USB Hdd) I could see some scenes (no action) are distorted (cubes), especially in bottom of the screen. I played it on my PC and connected it to Tv though HDMI 1.4 cable, but with the same result.
HD digital Tv signal from my local provider has the same distorted scenes time to time (DVB-C tuner)
I went to Samsung local store with USB Hdd - the same result occurred while playing on LED TV D6510 and D7000 (about 3000 $!)
When we tried play it on some cheap Samsung 2010 plasma - there were do distortion at all!!!
This is the advertized Samsung Smart Tv quality? (I'm about to return the Tv back)
Service guys, service hot line and local store guys here has no clue what it can be caused by. (2011 models are too new)
Thank you for your ideas and sorry for my English