pretending the device was an atmega328p and editing the device signature in the atmega328p entry in avrdude.conf
Well that's what I had done until now, that's because I'm looking for the answer since when I get the duemilanove attached I must go to the avrdude and change the signature again and again.Boring ]
I understand the compiler, the new entry for it is new, it must know how many pins, register and so on about this new device apart of being the same as the atmega328p his name must be diferent because of the signature differences.
I will still look for my answer 
Thanks anyway