What software are you burning with, that can make a diifference
Not all burning software is as compliant as the rest
Try IMGBurn if you haven't already, its 100% freeware and more importantly it works and produces very compatable burns
Just remember to change the burn speed otherwise it will burn at the medias maximum which may be to quick, are you sure you have told the software to burn at x2. Some software thinks it knows best and ignores what you tell it to burn at
I can burn at x8 with zero issues, on x16 DVD-R DataWrites. Verbs shouldn't give any issues, unless they are fake verbs .... it happens