Yves, I've never had any problems programming the NCE 408 but I have a NCE system. The NCE 408 decoder gives the motor a short pulse of electricity when you change one of the parameters such as the address. The very slight movement of the motor tells the user that the programming was accepted by the decoder. I am wondering if the 408 needs to have the motor connected to complete the programming task you are attempted to do. I've never attempted to program a 408 without the motor connected so I don't know if that is the error one would see. Either that or perhaps this particular decoder is bad.
I can't think of any reason why a Lenz system could not program a NCE decoder especially since as you mentioned you were able to program the smaller decoder. Hope this helps. Good luck.
