LG GSA-4167B Does not recognize 8.5 GB DL Disks

My LG GSA-4167B Internal 16x Super Multi DVD/CD Writer does not recognize 8.5 GB DL DVDS. I am able to read and write to 4.7 GB DVD. Any help in letting me know what the issue is will be appreciated.

Thanks
Guruprasad

What brand are the DL disks?

I have tried both Sony and Moserbaer.

Try some verbatim MIS