Burner wont read some dvds?

Hi there , just new here but i have been searching in the forums for a answer to my problem but havet managed to find it , i have a LG GSA 2164D burner and when i went to back up some discs i found a couple of them it wouldnt read or even reconise that it had a disc in there??? , i have downloaded the latest updates for this machine at the lg site but still hasnt helped.
Any sugestions would be greatly appreciated …

More info please.

source media
target media
softwares used

It happens sometimes cateltsen.
Either discs are not recognized by the drive because the firmware doesn’t have them in the list or due to quality issues (CD-R/RW or DVD-/+R/RW) or because they are not “good” anymore - all discs, including the ones from commercial stuff, can become useless due to “bad” isolation of the layer were the info stays (discs lifespan is not a constant).
Obviously, you can have system or drive related problems also. But, as you say you did update your drive you have to make atempts to sort them out.