Pbg4/837 Problem Reading 4x, 16x Data Dvds


My PBG4/837 (OSX 10.4.2) only reads 1x or 2x data DVDs in the superdrive. It won't read 4x or 16x data DVDs made on my PC. I'm wondering if there is a reason for this. I understand the write limitation. I'm talking about reading a data DVD. I did not realize there was a limit. If there is such a limit, that devalues the utility of the data DVD for my media backup. Is there a fiirmware/hardware upgrade need? Your thoughts?