I have recently ran in to a problem with Toast 9.0.2 and burning DVDs to Pioneer DVR-112D drives in Lacie d2 firewire/USB external cases. I have three Lacie d2 cases. One is older and is firewire only using an Oxford 911 chipset. The other two are newer and are firewire and USB using the Oxford 911-ATAPI chipset. The older, firewire-only unit works fine. The newer units always fail using firewire with the error "Mismatch at byte 0/sector 0. Verification failed." The burned discs are unreadable. Both of these units do work with Toast 9 if I use USB. Both units work fine with firewire and USB if I burn from the Finder. I have the same problem on my MacBook Pro and iMac. (Both are mid-2007 models, 2.4 Ghz, 4 Gb RAM running 10.5.3.) Problem occurs with DVD-R and DVD-RW media. Lacie and Pioneer firmware is up-to-date. The Lacie drive is the only device on the firewire bus.
These Lacie units have worked previously with Toast 8, however, I do not know for sure if they have ever worked with version 9. I have very recently rebuilt my MacBook Pro from scratch with a fresh format and install of OS 10.5 and a reinstall of all software. The iMac is new, so the installation conditions are the same.
In the process of troubleshooting, I reinstalled Toast 8.0.4 and it works fine. I also removed Toast 9.0.2 and re-installed 9.0.1, which acts the same as 9.0.2.
I am not sure what else to try. Any suggestions would be appreciated.