Pioneer DVR-106D and External Firewire

Please help!!
I recently bought a pioneer DVR-106D drive(firmware1.07) and an external firewire enclosure (OXFW911).
I upgraded my Nero to 5.10 so it now supports the drive, and have successfully burnt 2 DVD-Rs but now Nero tells me “Communication Failure” after 300meg - 1 gig, and spits out the DVD.
I’ve read (I think here) that the pioneer drives are not good with DMA but I can’t find any way of turning the DMA off on the firewire interface as it’s not an IDE channel. I assume that the problem is that the firewire OXFW911 chipset supports DMA and the drive doesn’t. Anyone else got this problem? or any ideas on a solution?