Hp dvd840e problem w/dl dvd burning

Hi, I have bought a HP dvd840E, the writer will burn cds and ordinary dvds, when i try to copyfrom a dvd+r dl it will read ok but seems to have a problem writing it as it stops and freezes at about 56%,I have ruined 4 discs upto now, I am using nero 7 and have got the latest firmware and i am using bulkpaq 2.4x dvd+r dl discs to write to, can enyone help please :sad: