How to disable the DHCP server in a KVM environment - part 2

It seems that the trick to disable the DHCP server by editing the XML file isn't working anymore. I tried it yesterday in my Fedora 17 x86_64 box and it didn't worked. The solution I found was disable the default virtual network, create a new one and disable the DHCP server in the wizard (when you create a virtual network the wizard shows you an option to disable it).