Burning problems with SM348 and Nero

i have a samsung SM-348, and im having trouble getting it to overburn.
im using nero (, multisession is off, using Disc at once.
but every time i burn the disk, it fails saying “Write error”

a few odd things ive noticed, im trying to overburn to 710mb on an 80min disk, however when nero is burning it shows it as 810mb
also ive tried burning with a simulation (which also fails) however it seems that it has burnt on the disk during the simulation (very odd!)
every time ive tried to burn using disk at once with this drive ive had errors.

i havent tried any other programs yet, but nero has never caused me problems before.