I have a Gigabyte's 9550D and couldn't flash to 9600 but now it's ok. I use the command:
flashrom -p 0 [filename] -sst -f
It need both -sst and -f, one parameter alone wont work.
Already flash to 9600XT, i used Gecube bios to flash with Flashrom. To flash with clocked BIOS like Gigabyte's, adding the parameters -sst -f . That's so simple but seem like noone here care to answer.
@ngocrebel: your name so familiar, u come from Vietnam ?