Strange Liteon sohw-1673S problem

I installed a Liteon SOHW-16773S yesterday to replace a Micro Advantage 88DVDRW.
I have many DVD-R data disks that I burned using the Micro Advantage and am unable to read any of them.
I am, however, able to read DVD+R, DVD+RW, CD-R disks burned with the Micro Advantage.
Also, I can burn a new data DVD-R with the Liteon, using a blank DVD-R from one of the same batches as the previously burned/unreadable disks.
I really need to be able to read these old DVD-R’s.
Called Liteon tech support last night, but they were of no help.
The Liteon manufacture date is May 2005. The wanted me to download the firmware on their site, but my drive has newer firmware.
Any suggestions? Should I just send the drive back to Newegg & try another?
Anyone ever see this problem before?

@ Dssenne
Welcome:). Are the dvd-r discs you burnt with the Micro Advantage burner that the Liteon cannot read, readable with the MA drive or any other drive? What are the dvd-r discs Media IDentification code(MID)

Thanks for the welcome.
Yes, I have no problem reading the dvd-r discs with the MA drive. I haven’t tried
using another drive yet (just installed the Liteon last night).
I’ll reinstall the MA tonight so I can check the Media ID. The discs are several
different brands, both “name brand” and cheapies.

@ Dssenne
Does the Liteon even recognize there is a disc in the drive? If so, you should be able to get an MID. Try using Kprobe 2.4.3 to get the MID. You can also check your burn results with Kprobe 2.4.3 BLER scans(scanned at 4x scan speed the forum standard for comparison). You can read Interpreting PI/PO error scans to find out what these graphs mean. PI/PO is now referred to as PI/PIF. Roughly, PImax<280; PIFmax<4. Attaching disc quality scans to your post of any offending discs will help us help you.

No, when you put a disc in the drive, the computer just hangs up until you remove it.
Just got off the phone with Liteon’s “second tier tech support”, but they weren’t able to help.