Xenoproctologist, thanks again. And thanks, Aktan for the explanation of cropping in Avisynth. I will learn how do it and you helped me to get started.
Xenoproctologist, I opened your modified .avs in VirtualDub and the "ants" are still there. Both areas, top and bottom, where the video meets black order are still affected.
I have uploaded a short mpg (eur.mpg)
A screen shot of your .avs opened in Vdub (eur.jpg)
A screen shot of the first workaround .avs (the strange doubled logos) called "first_workaround.jpg".
A troublesome "hybrid" clip (marvin.mpg)
Screenshots of your .avs loading the "hybrid" clip in Vdub (marvin1.jpg, marvin2.jpg)
In the "hybrid", there are "ants" in the non-full screen 4:3 scenes, where black meets the image content. I hope it shows well enough. Otherwise, I'll DivX encode a short example and upoad.
Here are the examples:
http://w1.837.telia.com/~u83704167/clip/
I appreciate your help.
/Swan