DVD media 4x -r works with DVR109 inside computer flawless, but does not read in 1:7 Duplicator/DVD tower – I appreciate highly all help and sugge...

I am a distributor in Morocco and I have had the bad expereince to purchase some 200.000 DVD-r 4x that seems to be somehow not living up to expectations:
1. I burn on my DVR109 completely new manufacture date april 2005 without any problems whatsoever, full movies with menu to full disc data and all works with no errors or problems whatsoever.
2. My clients are in majority resellers of duplicators and media, and I have now the problem that a 1:7 duplicator system with either newest Acard or Wytron controller do not read the media in all writers, although they are all DVR109 pioneer. The problems are like this: sometimes 3, sometimes 4 or or even 6 burns and then stops in the very end of burning. Sometimes it burns to the end but then maybe 2 or three. One client who uses duplicator 1:3 works fine without problems.
Conclusion: somehow it seems that when duplicator has to read a bigger amount of this media it starts to make errors, why I do not understand and figured it could be worth trying a controller with 64MB buffer memory, however, although not fully finished testing this type, it seems that also this does not work.

Does anyone know how to get past this kind of problem, so that I can eventually manage to have my discs sold?????

I will appreciate any suggestions or help possible, and thank you in advance.

I enclose the details of the dvd media I have, or at least the info I have from DVD identifier:

0000 : 01 40 c1 fd 9e d8 52 00 02 f7 0e 0b 77 88 70 00 .@....R.....w.p.
0010 : 03 00 00 00 00 00 00 00 04 00 00 00 00 00 00 00 ................
0020 : 05 aa a2 22 22 20 01 00 06 0b 0f 12 66 66 80 00 ..."" ......ff..
0030 : 07 88 80 00 00 00 00 00 08 01 1b 0b 0f 08 08 00 ................
0040 : 09 55 09 10 0b 90 88 00 0a 80 88 80 88 80 10 00 .U..............
0050 : 0b 00 00 00 00 00 00 00 0c 00 00 00 00 00 00 00 ................
0060 : 0d 00 00 00 00 00 00 00 00 00 00 00 ............