some blocks of the previous one remain above the video distorting it) even if perfectly encoded videos. (That on other comps works flawlessly)
Do you know the theory behind codec key- and bframes ? They´re the reason why codecs compress that good.
They take a frame and only save the changes of the frame for some amount of time.
What you have here is a keyframe problem I guess that may be the fault of CCCP. So when your scene changes than another keyframe "should" come along.
I´m no expert at this so please forgive me when I said something wrong .-.