I have a Plextor PX-708UF firewire dvd burner. gentoo-sources-2.4.22 includes ieee1394 support that works with this drive. Using gentoo-sources-2.4.25 the drive is listed on my scsi bus but does not function (a simple dd if=/dev/sg0 of=/dev/null won't work; nor will cdrecord or growisofs). The kernel config has not changes significantly between 2.4.22 and 2.4.25. I have the proper 1394, scsi, iso9660 and udf modules built and loading just fine. I may have had the device working with 2.4.22-r5 at one point but don't have that kernel handy to test with anymore (due to an NFS bug introduced in later 2.4.22 kernels that is resolved in 2.4.25; this is a diskless system)
(typo in initial submission. the dd is "dd if=/dev/sr0" not sg0)
Could you please try with gentoo-sources-2.4.26-r3, and if the problem still exists, try vanilla-sources-2.4.26.
gentoo-sources-2.4.26-r3 works fine for 1394 with my dvd burner. thanks. closing this bug.