I bought an NEC 3500A and it was unable to read 5 out of 10 of the maxel 4x dvd-r 's that i had data backed up on. The dvd’s were burned on an LG 4120 . The NEC was unable to read half the dvds and the system would get very sluggish as it tried.
So… I exchanged the drive for an LG 4160 and it can read ALL my dvd’s no problem. I didnt want to take a gamble on another NEC.
Just letting you know my experience for those who have the same problem.