Driving a silver 1998 Audi A4 2.8 Quattro... with a PES-Tuning supercharger setup. I understand.
Win64 is the devil, really, especially on a gaming rig. I seriously doubt this is a "64 bit" related issue, but I've seen crazier things blamed on it/caused by it.
Is the firmware you flashed still current? Unfortunately (I'm more familiar with Lite-ON's) this is a rebadged BenQ DW1640. Good drive, but I don't work with BenQ's enough (got a DW1650 about 3 days ago) to tell you what to do firmware wise, short of looking for a more up to date Sony firmware. It seems like 1.0E is current, though. I don't actually see it on Sony's site, only 1.0D, so it may be a beta or something.
You may want to consider getting a combo drive or a dedicated CD-RW drive, though, as I've noticed that my DVD-RW drives burn relatively poor quality CDs, even on good media. Never really figured out why, though. Music CDs in particular have a tendency to skip, but data is usually alright.
Anyway... update your IDE drivers if anything's available -- but NVIDIA, like Creative, is terrible about releasing updates... or even bothering to write them. Update Nero to the latest in the 6 series. Hope that sorts it out. If not, consider grabbing the 1.0D flasher from Sony or elsewhere and making sure it's not the 1.0E firmware causing the problem.