Sorry I forgot about this thread. I search every file in logs for "ignore dupe entry" and there is nothing to be found. I found one duplicate video and I tried to find it in files.
I search for ID of video (that text after "watch?v=" ). I search for name of videos and is all same. It finds only that part for downloading, nothing about skip, ignore,...) The problem is, that both videos have same URL.
I don't know why youtube allow something like that, have two videos with same URL.