I've got a wierd problem with my LiteOn DVD-163 drive. It will read CDs/CDR's etc just fine. But if I put in any DVD (Matrix, etc.) it can't read it. Acts like there's nothing in the drive. However, if I leave the DVD in the drive and reboot the system it will read it just fine and I can swap DVDs in or out. I can't figure this one out, I'm not sure if it's a bad drive or what. Anyone else had this problem?
Some specs:

Windows 2000 Server SP2
ASUS A7V mobo + Duron 800 O/C to 900 Mhz, latest BIOS 1011
HiPoint 370 IDE RAID PCI Card, 2 x 40 drives for O/S
Onboard IDE Primary: Liteon 24x CDRW Master
Onboard IDE Secondary: IBM 20 GB Master, Liteon DVD-163 Slave

I've got the latest firmware for the DVD drive. Windows shows DMA running for all IDE devices. I haven't tried moving the Liteon to it's own IDE channel as master yet. Doesn't seem like that would be the problem, seems more like the drive is only reading media properly on boot. Very strange. If I put in a DVD with the system running it won't read it. Also, it won't read any CDs afterwards either. I have to reboot the system to get it back to reading things. Any suggestions?

What's your power supply rated at?

It's a 400 watt model, Motherboard Monitor shows all the voltages are within spec. Case temp is 30*C and proc is heavily cooled. Interesting idea though, I never thought that DVD playback might need more juice than CD. I emailed LiteOn's tech support 2 months ago, but never heard squat back. Their 24x CDRW drive is great, never had a problem, but this DVD thing has me baffled.

Have you used any software to test the DVD like Nero? http://www.cdspeed2000.com/

I haven't used that tool specifically, but I have used another called CD check and SiSoft Sandra's CD benchmark. Both work just fine with a CD in the drive. But if I put in a DVD NT reports no disk in the drive and both utilities complain there's nothing in there to test with. If I leave the DVD in the drive and reboot everything will work fine.

Sometimes with DVD's they're looking for the Regional Code. Try putting in a DVD movie, which will unlock the code, then stop it and put in the data DVD.

The problem is reading DVD movies. I don't have any DVD-ROM (data) disks. The region is set to 1, which is correct. But putting a DVD movie disk in the drive shows nothing, acts like the disk isn't even there. Reboot with the disk in the drive and it'll work perfectly.

This utility is supposed to check the ACPI configuration: http://www.digitalconnection.com/drivers/aspichk.exe

Problem solved - It appears this was due to an older version of McAfee Netshield that I was running (v4.0.3). I noticed a message in the Event log that complained that NAIfltr was unable to read some UDFS file. Removing Netshield solved the problem. Supposedly there's a new version 4.5.1 of Netshield out, and I guess this would solve the problem, but naturally McAfee makes it a pain in the *** to get it. McAfee is the only company I know that makes it a big deal to get patches. I used to like McAfee but I think I'll find a different vendor now. Thanks to everyone who helped!