Cannot finalise DVD using Nero

[Obrent]

I am trying to burn dvds using nero but failing. Its giving the following errors

"Invalid block address"

"Could not perform end of disc-at-once"

HELP???????????

[setarip]

"'Could not perform end of disc-at-once'"

Did you try playing THIS burned DVD before tossing it? That error does NOT always mean a failed burn...