Verification of DVD=Read errors from sector 16 to 31

I had burn a DVD in iso mode at 4x. First time I gat Read errors from sector 16 to 31.

So I burn it again and got the exact same message Read errors from sector 16 to 31.

Si I am in doubt, how can this be possible ? I check the DVD every thing seem fine, is it Nero that doe the mistake ?