4120b:writing ritek r02 at 2.4x

when i write ritek r02 at 2.4x speed i don’t get any error from Nero, but the dvd is unreadable. i’ve tried with 2 different 4120b drives with different nero versions, dvd2copy and alcohol 120% in different computers getting always the same results. when i write ritek r02 at 4x the dvd is perfectly readable by 4120b, but when i play it in my panasonic home dvd player the movie goes jumping and stopping after about 1 hour and a half…
ok, i’ve understood that ritek r02 isn’t a good media for 4120b, but at least i should be able to write them at 2.4x!!! What can i do? i’ve bought a hundred of this media!!
I’ve tried firmware a102, a104, a110, a111 and the last a112 with always the same results…