I have a similar issue, so I won't start another thread as the advices might help both of us.
I have been using the following drive for over a year for DL burn w/ no problems. I bought a new batch of media of the same media type (number matches), and the DL burn would fail the first attempt at the second layer after a power on. However, when I retry a 2nd time the burn would work without changing any configuration. This was repeatable several times.
Having tired of wasting a DL disc per DVD image, I decided to try the following -- burn 1st image twice (as the first burn is always a coaster, the 2nd burn is successful), then burn a 3rd DL disc for the 2nd image, which proved to be successful as well. This shows that a failed burn is required for power calibration.
At first I thought this might has been a media issue, but now I don't think so. I looked at the logfile for anything that might differ between burn 1 & 2, but I didn't see anything different. I have pasted the log below. Any suggestions? Thanks.
-- initial burn, always a failure --
I 21:45:01 ImgBurn Version 2.4.1.0 started!
I 21:45:01 Microsoft Windows XP Home Edition (5.1, Build 2600 : Service Pack 2)
I 21:45:01 Total Physical Memory: 523,672 KB - Available: 285,008 KB
I 21:45:01 Initialising SPTI...
I 21:45:01 Searching for SCSI / ATAPI devices...
I 21:45:01 Found 1 DVD-ROM and 1 DVD