I'm burning them on a Pioneer 108 DVR with DVD Decrypyer at 2.4x, because with DVD Decrypter you can specify what sector to place the layer break at, I put it at the start of a scene where the prison guard says something about not being notified about a prison transfer.

edit: I got a reply from the place I bought the discs from, fat lot of bloody good that did me, all it said was that they're usually reliable discs and I should be using the latest drivers... no shit sherlock! think I'll put dual-layer on hold for now till the media is significantly cheaper and reliable, I can't afford this crap unless someone who can burn dual layers without a hitch can help me out? I can pay for blanks but not half a dozen coasters just for 1 burn that almost works