Comment 14 for bug 1003656

While doing some testing here I couldn't reproduce the whitespace issue, though I did find a bug matching your description that's related to our udev hooks.

Could you try doing the two following changes?

In /lib/udev/rules.d/40-bridge-network-interface.rules:
 - replace "bridge-network-interface" by "bridge-network-interface&"

In /lib/udev/rules.d/40-vlan-network-interface.rules (if you have it on your system):
 - replace "vlan-network-interface" by "vlan-network-interface&"

Then reboot to test with your config.

On my test system (12.10), this fixes it, another look at why indentation would fix it was unsuccessful, so hopefully that wasn't the actual source of the problem ;)