Jeffrey wrote:
“Could this possibly be a problem with my writer’s ability to scan for errors?”
Chef wrote:
“the Pioneer burners are not really useful for making quality scans.”
Franck writes : Chef answers your question and he’s perfectly right 
Pioneer burners are not very good scanners. As I mentioned in a former post, PIE errors reported are higher than on other drives, and the scans are a little erratic sometimes (sudden single spikes up to 900/100 PIE on perfect media). The 109 also seems more sensitive to heat than other drives and give me erratic scans when it’s hot from long use.
Sometimes I get strangely high PIE errors on good media, and if I just recycle the tray and rescan, the PIE max errors are half what they were before recycling the tray!! 
With the 109 and DVDInfopro, you may COMPARE different burns/medias but without an other method/drive to compare the results, it’s difficult to know exactly how to interpret these results.
I also have a Benq 1620 and scan my discs with it and CD/DVDSpeed, so I have compared many 109/DVDInfopro results and Benq/CDSpeed ones.
It’s the result of these comparisons (and consulting many Kprobe scans on this forum performed on same medias as mine burnt with the 109) that allowed me to state that when you do 109/DVDinfopro scans, PIE max about 50/60 and PO max about 10/12 is excellent. That should be your goal when selecting very high quality media. But you can live with PIE < 100 and PO <20, this would still be honorable results.
BUT still perform a tranfert rate test! PIE/PO/PIF scanning doesn’t tell everything about a disc quality/readability!!
My very best discs (TYG02, old stock Ritek G04, MCC03RG20 Verbatims, MIJ MXLRG03 Maxells) burned and scanned on the 109 read in DVDInfopro: PIE max about 20, average about 10, PO max about 8, average about 5.
I’m too lazy today to make a search on my other PC to post some scans - sorry 
Now to the total errors count, it varies so much between scans (even made with the very same disc!!) that I stopped looking at it. LOL 