Only disk-at-once for DVD-R

Hi.

I have some questions…

Writer : Pioneer dvr-107d
Firmware : 1.10
Nero : 6.3.0.3
Problem: I can only choose DAO method
(or better - I can’t switch another option - DAO
is selected and grayed=unfunctional)
for DVD burning (all types of media)
(in CD mode I can switch to TAO and DAO/96)

Could I something to do ?

THX