Could not perform end of disc-at-once-session fixation error with nero 7?

hello folks..am trying to burn a dual layer dvd using an hp dvd writer 630c9some refer to it as the 630i...anyways...i am using nero 7...it starts to burn the disc then 30 seconds later starts to write the lead out and says burn session failed as well as session fixation error and could not perform end of disc-at-once...I know the firmware is the latest version and although the burner came from an xp system,vista ultimate seems to recognise it MOST of the time..and am using Verbatim dvd+r dl discs...it fails with other software as well...anybody have any idea how to get this working as it's driving me nuts...please folks..If you are going to answer...at least say something intelligent..10 points to the best answer asap