I have the exact same problem.

tried a number of things to resolve it even contacting sony nec optiarc directly, stillw aiting to hear from them.

updated to both firmwares available on this site to no joy.

will happily write CD-R on 2 various brands.

however on 2 various brands of DVD-R fails with errors as above.

I have noticed tho, if blank CD is inserted my computer will display the free space, however on the DVD-R it will not, any ideas as this might be a good clue to resolve it?