LG GSA-4120B won't read data disks

I had a HP DVD200i for the past year or so with no problems. I just replaced it with a LG GSA-4120B and it won’t read all my previously burned dvd data disks. I burned them with HP DVD Writer and had no problems reading them in other DVD-ROM drives.

The disks I now burn (all are DVD+R’s), with Nero on the LG, are not recognized by other DVD-ROM drives.

I did find that the Maxell DVD+R’s I burned with the HP can be read by the LG, but other brands (Sony, TDK) cannot.

It originally had firmware A104 and I’ve recently tried A110 with no further success.

I’ve also tried disconnecting the CD drive off of the IDE controller and making the LG the Master instead of Slave.

System: Dell Precision 450, Win XP SP1.

Can anyone help?