I say this because I tried the following
I put 2 burned DVDs in seperate sleeves ( by themselves)
then I put 2 burned DVDs in the same sleep (back to back in the same sleeve)
and I get spikes in the middle of the quality Disc for the 2 DVDs that are in the same sleeve
when the solo DVDs ran the quality test perfectly.
I'm doing more tests, just wondering if someone is already on top of this