Flashing your drive
xtreme.bat automatically makes a backup of your dvd drive firmware called orig.bin.
Plug SATA cable from DVD drive to PC. Power cable drive still connected to Xbox 360
Ensure Hitachi drive is in mode b either by two wire trick or slax linux boot cd
Go to Windows
Run xtreme.bat batch file from a dos prompt specifing drive letter eg "xtreme.bat g"
Run restore.bat to revert to original firmware eg "restore.bat g"
Thanks to everyone at www.Xboxhacker.net for all their discussions. Thanksgo to Seventhson for flashsec and memdump and Loser for firmcrypt,without these tools this would not be possible.
Hitachi drive seems to be less tolerant of dual layer media. Try a few times to boot a backup.
Firmware for 46 version will be released soon but I cannot test it. Code is offset slightly throughout the firmware.