I have problems too.
I recently put a sony CRX160 into a friends machine.
Asus A7M266
T-bird 1000
256 PC133
Sometimes it will complete a CD, but mostly not. When I try to enable DMA on the drive it either causes a conflict in device manager on the seconday IDE controller, and both your CD-roms disappear (you have to remove the PCI IDE controller and reboot to get them back, and it takes DMA off again) or with the drive by itself DMA is enabled but locks up the system when you try to burn a CD and you must reboot. I was told to try the latest drivers for my motherboard, but that didn't change much.
I know this doesn't really help you any, but maybe I can get some help here, too. Have you tried enabling DMA? On another friends computer we couldn't burn above 4x of 8x until we enabled DMA.