Need help with hp dvd writer 400c

i need help downgrading my kh27 firmware to fh04 firmware so that i can burn dvd-r discs . i have already formatted my comp twice and it still didnt work. when i try to flash it to a PHILIPS DVDRW824DP Firmware it says: Linear Check Sum = 4F3C
Rotated Check Sum = 5A65
Check Sum match !!
Start Flashing…
Don’t turn off the power!!

======== FAIL 1========
i have contacted hp. they keep on asking why do you want to downgrade it. they were no help. some1 plz help me :bow:

Try reading through everything in this thread:
HP 400c to Philips 824p ok - BenQ no go !!!
This is the most comprehensive collection of flashing information on CDFreaks relating to cross-flashing the HP400C