NEC 3520A burns, plays DVD+DL - Error

NEC 3520A burns, plays DVD+DL, Explorer won't read it though

I copied (using Nero 6.6) my Apocalypse Now Redux DVD on to a RiData DVD+DL (2.4X) using my NEC 3520A. This is in my MSI mini computer (2.8GHz) running XP Pro. It seemed to copy OK but it wouldn't verify and CD Check reported it couldn't read anything right. If you then use Explorer to try to read the disc it reports that you have a blank disc in the drive. But amazingly, it will play the disc using Cyberlink Power DVD 6 or Nero 7. It is very slow and hesitant to start playing and it doesn't exit very quickly (hangs) using either of these programs, but it does play OK once it starts right to the end.
I changed my Firmware five times (latest is Liggy & Dee NEC ND-3520A 3.06 firmware) in the NEC drive, and the results were the same every time. DVD Disk Info shows it should read every DVD type except DVD-RAM but it doesn't mention DVD+DL discs. It does play original DVD 9 (which are dual layer) movies and Explorer reads these files OK. I have another Computer (1.8 GHz, XP Home) with a PIONEER DVD-ROM DVD-304 SCSI, a SONY DVD RW DRU-510A and a SONY DVD RW DW-D18A. All of these drives read in Explorer OK and play the disc OK using Cyberlink and Nero 7. I ran CD check in the Pioneer DVD-304 and it reported that the disc is perfect.
I guess the question is, is my NEC drive defective or is this how a NEC 3520A drive works? Has anyone burned a DL RiData 2.4X disc with a NEC 3520A and had the same problem? Any suggestions are welcome. Thanks, Dave

Crap quality media, use Verbatims.

I RMA'd my defective 3520A drive with NewEgg. In less than ten days I had a new replacement 3550A installed in my system. It works flawlessly, either burning or reading. It reads and plays the discs properly, both starting and exiting, and Explorer now reads the DL files on the disc. My only cost was for paying to return the defective 3520A to NewEgg. They FedEx'd the 3550A to me on the 13th and I received on the 15th.
I had bought the drive in February and it appeared to work perfectly but due to the cost of DL discs I waited until November to purchase any. Only then did I discover that it was defective. Besides the fact that Explorer couldn't read the burned DL discs, none of the benchmark/testing programs could read or check them also. Dave

A drive not burning Ritek DL is working correctly, and we'll see for how long you can read them now