Thanks Ian and MediumRare,
I have two Primary IDE channels, one for my SATA drive and one for my primary IDE slot. I have my HDD in the SATA one and my Lite-On drive in the other (I have a secondary also, where my other Lite-On 52327S resides). In my BIOS, the DVD-RW appears in IDE 1 and the HDD in IDE 3.
Anyway, it appears as UDMA 4, so I think I'm good there.
I have enabled the real speed feature in Nero, and the burning usually starts at 8x and works its way up to 15x with this Verbatim 16x DVD-R media. For what that's worth.
I may be getting buffer underruns, but I don't know how to tell exactly or what to do about them. I don't know if the fact that the drive has only 2MB buffer matters or not (I have one gig regular memory and a 2.80 processor).
Any other ideas?