Hi...
@KillMe: i've used the same disc (Prime Disc 8x DVD+R) from the same batch, burned them with
nero cd-dvd speed (the max. speed reached you can see on the first pic).
I think that the high PI in the range from 3.6GB up to 4.37 GB is because of the defect on the media. I will try an other from the same batch to verify it but i've no luck with that batch 3 out of 20 showed that dark lines from the middle to the outside. One in the inner area, two on the outer area.
Regards,
Gerd
PS: What might be the reason for that "straight lines"? They look like drawn with a ruler. Manufacturing errors? Because "burn rings" are around the hole and not straight lines i think...