The burning process depends on the burner/firmware/media combination, and since your burner already has the latest firmware, the problem is either the blanks or the burner itself. You need to try your blanks on another BluRay burner to see if they will work or not.
Does any of your family or friends have a BluRay burner? You could also try lending/renting a BluRay burner from a computer store or something like that.