The vlan labelled unrouted is the layer 2 vlan and the other is the layer 3 vlan.
It seems to me you may not have set the ifindex persist command on your routers/switches. The command on a cisco device is:
snmp-server ifindex persist
This command persists interface index snmp uses when asking the device for statistics on a specific interface,
I have verified that the switch in question has snmp ifmib ifindex persist on it.