If you're using Primo, it still has trouble with some newer drives even with the PX update. You might need a newer Record Now version of it--they doesn't rely on the PxEngine as much. The RN-DX 4.11 that came with my A04 has worked with nearly every drive I've come across without updating it. You could also try the DVD-Decrypter in ISO mode. It's free and you can select the different ATAPI/ASAPI/CDIO drivers available on your system.
If it ain't broke don't try to fix it! But, hell if you can tweak that bastard just a little bit more....hehehe.