Drw-1s81 write in 1x?

hi, i would like to know how to write dvd in 1x whith nero or roxio easy cd, because i can’t.
i have liteon drw-1s81 whith latest firmware
for people who doesn’t know drw-1s81 it is the same litron ldw811 but it is remanufactured
thanks you for answer
please excuse me for the english i am a stranger
i can only write dvd in 2.4X or 4X whith nero
it may exist other software for write *.iso
see you soon

the slowest speed for dvd +R is 2.4x, 1x can’t be done.
the slowest speed for dvd -R for recent firmwares is 2x even if its a 1x disc.
so 2x and 2.4x are the slowest you can have. These speeds should be fine for everything though.
If you have problems with movies playing back properly, use different (better) discs, not slower speed.