I agree that the DVD drive should not be connected to one of the 4 sata ports supported by the ICHR9 chip, which is indeed running in RAID mode, not ACHI. This is why I plugged the dvd drive into the 5th available non-raid sata port on my mobo which goes to a Marvell 88SE6111 chip. According to the mobo docs, this is the preferred connection for a DVD drive.
As I stated earlier, the Roxio works in this configuration, I have sucessfully burned 3 discs now, even using this 'cheap' media. I have been using the same cheap media for at least a year now and have burned literally hundreds of discs, with very few failures. Most of what I burn is downloaded junk and not all that important. Anyway, in this config, Imgburn hangs the PC. I agree that Roxio probably does not issue that same command, or it too would hang.
I moved the drive to the 4th sata connector (part of raid set) just to try something, not because it is right. In this config, both Roxio and Imgburn start burning, but both have trouble at almost exactly 2 TB. I think this is not a good config to run, I moved the DVD back to the 5th sata non-raid port.
The drive is an HP OEM from a friend, he took it out of an HP workstation. I am rather sure HP gets their drives from LG. I suppose if you got your hands on a drive exactly like mine, you could resolve the problem rather easily, being such a talented coder.