My FireWire DVD-R Seems To Have Crapped Itself


Barking at the moon.
I bought this external drive from Other World Computing a few months back. It worked great the first few DVDs I burned (both data and video). Now, for some reason, it's burned about a dozen coasters in a row. Here are the specs:

Pioneer DVR-109 (FireWire 400)
eMac 700 w/ 640 mb RAM
MacOS X 10.4
Toast Titanium 6.1
Dragon Burn 4.1.16

I've trieid both programs and the finder, none seem to work. When I have Toast verify the DVD it usually comes back with a "bad sector 0" error or something like that. I'm using Patchburn, if that means anything to you. Man I hope someone out there can provide me a little insight because I just don't know what to do and am hoping the drive itself hasn't gone bad. Thanks!!
Are you doing anything while the discs are burning? Have you turned on buffer underrun protection?