
Figuring that I probably had some sort of firmware issue, I downloaded DVDInfoPro and was surprised to find out that those drives did NOT indicate support for DVD+R or DVD+RW. Drives that recognized DVD+ media and passed all of the PC Doctor tests did indicate support for DVD+ formats in DVDInfoPro. I contacted one of the eBay sellers and asked if it was possible to exchange the two drives I bought from him for a newer firmware version and was told that, "The auction ad specifies what these drives read. The DVD+RW and DVD+R are not listed in the ad." and therefore falls under their "no return for compatibility issues". Never mind that the auction description ALSO does not explicitly mention DVD-R or DVD-RW as being supported. So I suppose if I had a problem with those types of disks, I would also be out of luck for a return/exchange.

At any rate, I will document the revision levels and label markings on the drives to determine if there's a fool-proof way of knowing which drives can read DVD+ media. At the moment I think IMB0 and IMC0 can be used as a guide, but I need to test all of the drives I have to be sure. More to follow...
(ref: http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0136964046)