I have 3 T1's in a MLPP bundle. I noticed that 2 of the 3 serial interfaces have "ip load-sharing per-packet" defined. Is the config ignored whenever the serial interfaces are part of a multilink bundle? The multilink interface does not have this defined.
You are correct that if load-sharing per-packet is configured on the serial interfaces that are part of a multilink bundle then the load-sharing command is ignored, since the serial interfaces are not routing packets.
My suggestion is to remove those config statements from the serial interfaces. They are not changing the forwarding behavior but they potentially introduce ambiguity about the behavior.