if that indeed turns out to be the case, a workaround that can be used:
you create two .reg files, one of which enters into the registry the serial key of Nero #1, the other enters the serial key of Nero #2.
whenever you want to use either burner, you double-click the first or second .reg file to enter the appropriate serial key into Nero so it will recognize the drive you are about to use.
One Ring to rule them all, One Ring to find them,
One Ring to bring them all and in the darkness bind them
In the land of Mordor, where the Shadows lie
M.C. Escher - Reptilien