I think I read online that they are not alone in having this problem
In practice, the raspberry with raspbian takes the ip from dhcp and ignores the file /etc/network/interfaces
Here is how I write in the file:
iface eth0 inet static
address 192.168.17.150
netmask 255.255.255.0
network 192.168.17.0
broadcast 192.168.17.255
gateway 192.168.17.1
Has anyone solved?