Are you using Firewire 2.4?
According to MacFixit, there is a known conflict between Discribe and Firewire 2.4. The following is quoted from MacFixit:
CharisMac technical support replies:
"We just recently learned of this issue as well. However, the FireWire driver, called 'Spressa i.Link Enabler,' is not written by CharisMac, but by the company that manufactures the FireWire bridge that ships with the Spressa solution. The bundled Sony Discribe software doesn't care what version of the FireWire software the user has installed.
Having said that, I can assure you that Apple, Sony and CharisMac are aware of the problem and looking closely for a solution. Currently, the only known workaround is to downgrade to version 2.3.3 of the FireWire software. [If you don't want to or can't use the International English version just posted], you can use TomeViewer with the Mac OS 9.0.4 update and extract the two files you need (FireWire Enabler and FireWire Support) to get it all working."
The solution: downgrade for now to the earlier Firewire.
FWIW, I use the Sony CD-RW with Toast 4.1 and it works beautifully.