In my case the disc also FAILS, its not readable after finishing!
Burning an *.ISO file to a DVD-RW via the "Nautilus context menu", it gives the same error mentioned in this topic, only when selecting the lowest write speed. The resulting DVD is not read-able so burning failed.
Selecting the MAX speed does eject the DVD after writing "without the eject error", but also delivers a DVD which cannot be read by the OS or booting by BIOS!
Burning the disc from 'terminal' with the following command works fine, although there is no LABEL:
cdrecord -scanbus #look at CD/DVD burner device location nr
cdrecord -v -dao dev=3,0,0 Downloads/lubuntu-10.04.iso #my device nr was 3,0,0