These are scans of INFOME R20 DVD+R 8X media (Emgeton DVD+R 8X) burned at 12X with BenQ DW1620 B7T9.
These media are from 100pcs spindle. Some of them have those PIF peaks, which cause serious playback problems. On the other side, the rest of them is perfect. It seems that 1 of 5 discs is bad (I have burnt 15, 3 were bad so far - I don't know about the rest of the spindle now - I will keep you informed here)