I have the same problem with my 9 month old LG GSA-4081B DVD drive. It was working great until about a week ago. Now it only reads and writes CDs.
I am currently running on firmware A104. I have the latest IDE drivers on my nVidia n-Force2 motherboard and the drive is running on Ultra DMA2.
I have the latest registered version of Nero 6 and Power DVD installed.
The drive just does not see any recorded or blank DVDs.