OpenFlow 1.3 plugin does not discover topology with mininet 2.0 on Ubuntu Precise

Hello,
The OpenFlow 1.3 plugin does not discover the topology with mininet 2.0 on Ubuntu precise. How to reproduce:

Download the controller from http://nexus.opendaylight.org/content/repositories/opendaylight.release/org/opendaylight/integration/distributions-base/0.1.0/distributions-base-0.1.0-osgipackage.zip

and run it with ./run.sh -of13

Install Ubuntu Precise 64 Bit. And issue the following commands:

apt-get install mininet
service openvswitch-switch start
cat > mininet_sample_topo.py <<EOF
from mininet.topo import Topo

class SampleTopo( Topo ):
"Simple topology"

def _init_( self ):
"Create custom topo."

1. Initialize topology
   Topo._init_( self )

1. Add hosts
   h1= self.addHost( 'h1' )
   h2= self.addHost( 'h2' )
   h3= self.addHost( 'h3' )
   h4= self.addHost( 'h4' )
   h5= self.addHost( 'h5' )
   h6= self.addHost( 'h6' )
   h7= self.addHost( 'h7' )
   h8= self.addHost( 'h8' )
   h9= self.addHost( 'h9' )

1. Switches
   s1= self.addSwitch( 's1' )
   s2= self.addSwitch( 's2' )
   s3= self.addSwitch( 's3' )
   s4= self.addSwitch( 's4' )

1. Add links
   self.addLink( s1, h1 )
   self.addLink( s1, h2 )
   self.addLink( s3, s4 )

self.addLink( h3, s2 )
self.addLink( h4, s2 )

self.addLink( h5, s3 )
self.addLink( h6, s3 )

self.addLink( s1, s2 )
self.addLink( s1, s3 )
self.addLink( s2, s4 )

self.addLink( s4, h7 )
self.addLink( s4, h8 )
self.addLink( s4, h9 )

topos =

EOF

(ubuntu) [/root] mn --custom mininet_sample_topo.py --mac --topo sampletopo --switch ovsk,protocols=OpenFlow13 --controller remote,ip=<ip>

Find the log file attached.

Cheers,
Thomas