It's been a while since I tried to do simulation for DVD Media, but if I remeber correctly there is a reason why we no longer support Simulation to DVD media. If my memory is not faulty, and we do not support this for DVD Media any longer, I will ask that they gray this option out whenever DVD is selected, so that users can not even select the option so as to avoid confusion.
I do know that in Nero Burning ROM, the simulation option is grayed out when it detects DVD media in the recorder. However, if you do not have any media in the recorder, and you select Data DVD, it does offer Simulation again, till you insert the DVD Media that is.
I will get this explanation from our Engineers in Germany, and post it here.