Comment 22 for bug 184711

Variant here:
Running Hardy.

I needed to change from 100MBps to 1000MBps.
Shutdown, replaced the Intel Pro/100 NIC (removed it) for a Pro/1000, fixed the DHCP so the machine kept the same IP.
At reboot, the machine had detected the new NIC and assigned it to eth1.
The network worked.
But the "Configure" button in Networks Tools behaved as reported here.
Incidentally, /etc/network/interfaces was still referencing eth0. Changing it to eth1 didn't make anything better (even after a reboot) - at least anything obvious.

I manually put eth0 back in interfaces, shutdown, removed the Pro/1000 for the original e100b NIC, fixed the DHCP server accordingly: The machine went back to using eth0. But the problem persisted (same "The interface does not exist" message.
So it looks like I'm just in the same situation as anyone else here. I might just have got there using a slightly different path.