docker daemon/ iptables error when running dray with flannel

[clausqr]

Hi, I'm running a CoreOS cluster with flannel for networking, and when running the panamax unit files with fleetctl I stumbled upon this dray related error:

$ docker run -d --name reds reds  
/^[a-f0-9]{32}$/  
$ docker run -d --name dray \  
>   --link redis:redis \  
>   -v /var/run/docker.sock:/var/run/docker.sock \  
>   -p 3000:3000 \  
>   centurylink/dray:latest  

Error response from daemon: 
Cannot start container /^[a-f0-9]{32}$/:  
iptables failed: iptables --wait -t nat -A DOCKER -p tcp -d 0/0 --dport 3000 -j DNAT  
--to-destination 172.18.0.190:3000 ! -i docker0: iptables: No chain/target/match by that name.  
 (exit status 1)  

Is it a flannel issue? Looking around dray I can't find where this iptables call joins the party, nor where to run something like iptables -L ,,, any ideas?