DVD Fails to Read

Software: (Dual boot)
Windows Vista x64 Beta 2
Windows XP x86 Professional

Hardware:
Asus A8V socket 939 mainboard
-onboard AC'97 Audio
-onboard Marvell Yukon 1GB nic
AMD Athlon 64 X2 4400+ 2GB L2 939-pin cpu
2x 512MB Corsair PC2700 mem (for now)
BFG nVidia geForce 7800 GSOC AGP 256MB video
2x Maxtor 80GB ATA133 7200rpm hdd
ASUS DVD-E616 dvd-rom
Sony 52x/32x/52x cd-rw

Problem:
I have intermittent read problems with my ASUS DVD-Rom in Vista, but works
perfectly under WinXP. I can read CD-ROM, -RW, etc. with no problems on both
the ASUS and Sony, but DVDs will only intermittently read on the ASUS. 99
times out of 100, when I insert new DVD media the drive sounds like it is
making multiple attempts to refresh the disk when I insert it, and
eventually, Vista will fail the drive out completely and remove it from the
hardware list. I can boot to Vista with a DVD in the drive and it will read
without problems, but inserting a new DVD while Vista is already running
usually results in the continuous read retries.

If I have Computer up when I insert new DVD media, it will hang completely
and require Vista to recover Explorer.

I've experienced the same problem with the current mainboard and CPU and
with older ASUS A7V333 and AMD 2200+ running Vista x86. Yet the DVD runs fine
under WinXP Prof. and Home editions.

Troubleshooting attempts:
I've set the DVD to master and slave both with the Sony and without. I've
replaced the cable. I've removed the device from Device Manager, rebooted,
and let Vista redetect it. I've attempted to update the drive firmware, which
is currently rev. Z.0, but the ASUS firmware updates will not update my drive
(may be indicative of a problem??). I don't have another DVD-Rom drive to
test with.

One thing I can do to "workaround" the problem is to either allow Vista to
fail the device or manually remove it, then I can run "detect hardware
changes" and Vista can see the new media. As long as I don't reboot, I can
now insert new DVD media and Vista will refresh it properly. But, as soon as
I reboot and try new DVD media, it goes through the detect retry process all
over again.

Sounds like a driver issue to me as WinXP does not do this. Anyone seen this
problem before?