Finally I have got the total problem solved and Debut works perfectly.
Trying to find why Debut needed the previous starting of AmCap, I went to CameraConfig (a text file) in the folder of AmCap. There I have found more than 200 paramethers whose meaning just God knows; there also were two or three executable files with reference to 3288. Trying to make it up I have searched in Google "CameraConfig for 3288"; there appears a Russian page with a driver for this software. Downloading it has been said: "This program already exists, if you follow, it will disapear". I said OK, the file has been downloaded, uncompressed and finally installed. At the end:
1) No AmCap exists.
2) Debut Video Capture works alone and completely OK so in audio as in image.This was the target.