Having trouble making Vista recognize DVD-RW drive as recordable

I'm using Vista Ultimate with an Asus P5B Deluxe motherboard, and two DVD
drives connected to the JMicron IDE controller on the motherboard. One is a
player, one a recorder.

The problem is within Vista both only operate as players, Vista fails to
recognize the DVD +/- RW drive as a writer. I've read/studied/tried KB
article 316529 about CD-RW drives not being recognized in WinXP, however the
Volume{GUID} registry key doesn't even appear under the registry key in
question in Vista, so the article didn't solve my problem.

I have exactly the same problem with my NEC 3550A DVD burner, as with
another writer I switched out and tried, a Sony DRU-510, both of which were
simply seen as players, and not burners. I've tried deleting the drivers,
reinstalling, updating, and many reboots.

However, the 30 day trial of Nero 7.7.5.1 does work, seeing the drive as a
burner, and correctly burning disks, and erasing RW disks.

So it's certainly not a hardware problem, as both of these writers used to
work in XP, and they work with Nero in Vista - so what do I need to do to get
Vista to recognize the drive as a writeable?

Thanks,
roland at woosters dot com