Correction: the problem returns when the interface is *defined* in /etc/network/interfaces like this:
iface eth0:1 inet static address 192.168.1.1 netmask 255.255.255.0
Correction: the problem returns when the interface is *defined* in /etc/network/ interfaces like this:
iface eth0:1 inet static
address 192.168.1.1
netmask 255.255.255.0