I have two different DVD writers and two different packs of DL discs and I can't get a good burn out of any of them. I'm using Nero CD/DVD Speed Disc Quality test and generally the burns get really bad towards the end of the first layer, and then the 2nd layer is poor all the way thru.
Here's my stuff:
Pioneer DVR-108, Firmware: 1.18
Plextor PX-708A, Firmware: BSRB (BenQ DW1640), also tried PX 1.02
Verbatim DVD+R DL (MKM 001)
Memorex DVD+R DL (Ritek D01)
Nero Burning ROM v22.214.171.124
Windows XP Pro SP2
If I run QScan before the burn, the Verbatims don't pass and the Memorex barely pass.