I've just checked the plextor website and they have new firmware for this drive. 1.04 Released on the 21st
New Features:
・ DVD+/-R 16x: Added support for new media
・ DVD+RW: Added support for 8x media
・ DVD+R DL: Added support for 6x write (recommended media only)
・ DVD-R DL: Added support for 2x write
Improvements:
・ DVD+/-R: Improved writing quality
・ Improved writing quality of AUTOSTRATEGY (writing speed is raised up to Max12x on 16x media)
・ Improved reading quality
http://www.mta.co.jp/firmware/firmware.html