Comment 3 for bug 417383

NM has been ignoring interfaces listed in /etc/network/interfaces for a while now, I think we can consider this bug closed and Fixed.

One thing that comes to mind however is that NM might be failing to understand the bridged devices and still think of eth0 as a valid, single interface if there is no "auto eth0" entry, or if it just can't parse the config for the bridge.

Also, you can now create bridges directly in NetworkManager, which is another way to avoid running into this kind of issue.

Closing as Fix Released; please feel free to reopen / file a new bug if you run into further issues with bridging and NetworkManager.