Burning method slightly odd.
Use DVD-Shrink to rip, shrink, and automatically send an ISO to DVDDecryptor for burning in ISO Write mode. You can also have RecordNow (if available) burn the resulting ISO files onto disc.
Princo media. That will provide extremely variable results.
Philips media. Not bad, but it is CMC and needs for each finished disc to be ripped (into a temporary directory that you will later empty) with decryptor to check data integrity after each burn. That's just a CMC issue. CMC's always scan nicely, but it may be data-soup, so do a copy-back test.
Samsung media=not recommended because this is not always TY code. You need a "known good" and this isn't it.
Verbatim, Fuji, Ritek= A great place to start. Get some of these in DVD+R and you'll be pleased. Plain Prodisc that is not inkjet printable is of decent quality.
Again, use DVD+R because they are automatically bit-set to DVD-ROM so they can work with everything (although this bit-set is user-adjustable with the bit-set util or the tiny "book" icon in DVDDecryptor ISO Write mode). And, it is somewhat more difficult to purchase junk DVD+R discs (better odds anyway).