DVD will not verify

I have a new Gateway computer with a Hitachi GSA-4163B burner which is capable of Burn-at-Once DVD burning according to the specs. I have burned a CD with Burn-at-Once setting and verified the burn. For DVD burning the Burn-at-Once option is grayed out in Nero. I have been unable to make a data (or video) DVD that Nero verifies
as good. I think I have Nero (at least it says that in one place). I tried the BLANK DVD NERO.nrc, but that didn’t help.