Did you install the drive first then install the Nero software?? If so you may have experienced the same thing I did with the H54L. LG had to replace the drive with an H55L. They mentioned firmware corruption by the Nero Install. It plays DVD movies without any software installs. It needs only the generic XP drivers. If you didn’t you may still have a bad drive.
Try it on another machine. Just plug it in and test it with a player. If it still doesn’t work, replace it.