I purchased some new Dynex DVD+R DL discs to burn

I purchased some new Dynex DVD+R DL discs to burn some iso files, but the 3530a won't recognize the discs in the drive. I've tried using Nero, ImgBurn, and Alcohol 120%, but all of these programs are still giving me errors that the "drive is empty" or there is "no disc" when there is a new dual layer disc in the drive. The dvd-rom drive works well with single layer discs. I had recently updated the firmware to 3.01, but it doesn't work. Help!