Hi, people I was wondering - can anyone explain to me why are there "shifting artifacts" on some discs - usually they are in the scenes when camera is slightly changes position - and part or some parts of the picture is shifting. Sometimes it is terribly annoying. The recent example of where there are A LOT of such annoying artifacts - IMAGE disc "The House With The Laughing Windows". So - I guess that it is just a lousy compression job - but I'd like to know the technical explanation - WHY are such crap happening and is it possible to COMPLETELY avoid such kind of crap? And if yes - it is possible - why the quality control is silent when such issues are clearly visible in the final product. Would like to have some replies Thanks in advance!