It seems that the BenQ drives have issues with Pioneer -R burns. This tends to point to the overall unreliablity of scanning -- you are scanning how well the drive reads the disc and not how well it is burned.
I've burned another Verb -R with the Pioneer 117D, and I've scanned it with my usual Lite-On (which after going though many models I've decided to be my trusted scanner). I've also scanned it with the BenQ 1650, and two different versions of the Optiarc 7200. Clearly the disc is not bad since both Optiarcs were able to read it reasonably.
MID: MCC 03RG20 MAP7 CMC made
50 Pack Verbatim Branded from Fry's (new packaging)
Type: 16x DVD-R
Burned With: CD Speed 18.104.22.168
Drive/Firmware: Pioneer DVR-117D/1.06 stock
USB NEC enclosure