Comment 2 for bug 1164812

I've copy pasted Ian's explanation of what he did here. All I've done is made the config optional.
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That 'fix the network interface numbering' stuff requires we install this. Basically the init script ordering is:

networking - apply /etc/network/interfaces

openvswitch - start OVS daemons. OVS switches are created per the persistent OVS database. Interfaces are put into those switches per the OVS database.

... at this point in our setup, bond0 goes into br-internal and the address on bond0 becomes unreachable.

openvswitch-fix-interfaces - our custom script per above. We do the same network address moving that we did when we initially put bond0 into br-internal - that is, remove the address from bond0, put it onto br-internal, and bring br-internal up. The address is on the equivalent interface and is now reachable as br-internal actually terminates packets.