I did not try 18.104.22.168, but it looks like the same story.
I did not get any response to my question, so I posted the same question over at the CDRLabs forum. Believe it or not, here is the answer that I got from CCampbell, who is a Nero representative.
This is the response that CCampbell got from the Nero Engineers in Germany:
The response is: "Simulation is allowed on some DVD+RW media for some recorders and on DVD-R always".
So this is not a bug but normal operation.