Replying to my own post just to say I fixed it for the benefit of anyone else that may run into this issue.
Thanks to those that replied. The problem was that the initrd contained the persistent-net-rules from the host system. Trouble only occured when the the disk generation and the boot were done on the same machine (after swapping disks). In this case the udev in the initrd was renaming the initially detected eth0 to eth1 (since its mac address matched) The solution was to add a script to /usr/share/initramfs-tools/hooks to delete the persistent-net-rules file during initrd generation (similar to the existing udev one) in the chroot used to generate the disk. Martin -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]