LDW - 851S BookType BitSetting

Hey Guys,
One simple question about the 851.I have the latest firmware (GS08).The BookType Bitsetting apparently doesnot work with this firmware.So Can I change it to some other firmware(downgrade the firmware) that supports it without damaging the drive and will I be able to go back to GS08 or later sometimes in the future?

Thanks

Why is this thread necessary after your post below? GS08 is not the latest firmware.

http://club.cdfreaks.com/showthread.php?threadid=88077