Event dispatcher found no handler for NorthboundEvent

While running integration test on the ovsdb netvirt piece, we hit those issues:

2015-07-08 12:48:15,973 | WARN | ntDispatcherImpl | EventDispatcher | 271 - org.opendaylight.ovsdb.openstack.net-virt - 1.1.1.SNAPSHOT | event dispatcher found no handler for NorthboundEvent [action=ADD, port=NeutronPort [portUUID=8ddd29db-f417-4917-979f-b01d4b1c3e0d, networkUUID=7da709ff-397f-4778-a0e8-994811272fdb, name=, adminStateUp=true, status=null, macAddress=FA:16:3E:7E:A0:D8, fixedIPs=[Neutron_IPs

{ipAddress='192.168.111.21', subnetUUID='00289199-e288-464a-ab2f-837ca67101a7'}

], deviceID=e09818e7-a05a-4963-9927-fc1dc6f1e844, deviceOwner=network:router_gateway, tenantID=, floatingIPMap={}, securityGroups=[], bindinghostID=, bindingvnicType=normal, bindingvnicType=normal], subnet=null, router=null, routerInterface=null, floatingIP=null, network=null, loadBalancer=null, loadBalancerPool=null, loadBalancerPoolMember=null]

2015-07-08 12:48:16,066 | WARN | ntDispatcherImpl | EventDispatcher | 271 - org.opendaylight.ovsdb.openstack.net-virt - 1.1.1.SNAPSHOT | event dispatcher found no handler for NorthboundEvent [action=ADD, port=null, subnet=null, router=null, routerInterface=null, floatingIP=null, network=NeutronNetwork [networkUUID=12809f83-ccdf-422c-a20a-4ddae0712655, networkName=net1, adminStateUp=true, shared=false, tenantID=cde2563ead464ffa97963c59e002c0cf, routerExternal=false, providerNetworkType=vxlan, providerPhysicalNetwork=null, providerSegmentationID=1062, status=ACTIVE, subnets=[], myPorts=[], segments = null], loadBalancer=null, loadBalancerPool=null, loadBalancerPoolMember=null]

2015-07-08 12:48:15,738 | WARN | ntDispatcherImpl | EventDispatcher | 271 - org.opendaylight.ovsdb.openstack.net-virt - 1.1.1.SNAPSHOT | event dispatcher found no handler for NorthboundEvent [action=ADD, port=null, subnet=NeutronSubnet [subnetUUID=00289199-e288-464a-ab2f-837ca67101a7, networkUUID=7da709ff-397f-4778-a0e8-994811272fdb, name=subext1, ipVersion=4, cidr=192.168.111.0/24, gatewayIP=192.168.111.254, dnsNameservers=[], allocationPools=[NeutronSubnetIPAllocationPool [start=192.168.111.21, end=192.168.111.40]], hostRoutes=[], enableDHCP=false, tenantID=cde2563ead464ffa97963c59e002c0cf, myPorts=[], gatewayIPAssigned=false, ipv6AddressMode=null, ipv6RaMode=null], router=null, routerInterface=null, floatingIP=null, network=null, loadBalancer=null, loadBalancerPool=null, loadBalancerPoolMember=null]

Those logs comme from [1] (stable/lithium)
Note: this issue has been seen on stable/lithium and master

[1] contains the complete karaf log stable/lithium
[2] contains the complete karaf log master
[3] robot test cases that are run against ovsdb netvirt

[1] https://jenkins.opendaylight.org/releng/view/ovsdb/job/ovsdb-csit-1node-cds-netvirt-all-stable-lithium/37/artifact/karaf.log
[2] https://jenkins.opendaylight.org/releng/view/ovsdb/job/ovsdb-csit-1node-cds-netvirt-all-master/68/artifact/karaf.log
[3] https://git.opendaylight.org/gerrit/gitweb?p=integration.git;a=tree;f=test/csit/suites/ovsdb/Openstack_Neutron;h=10d604638defc2928bc5b8d73afb0dda46b726be;hb=HEAD