Singleton conflict in pax-url-war

Sometimes after a fabric:create I get:

2014-08-21 17:25:42,364 | ERROR | agent-3-thread-1 | DeploymentAgent | 83 - io.fabric8.fabric-agent - 1.1.0.redhat-015 | Unable to update agent
io.fabric8.common.util.MultiException: Error updating agent
at io.fabric8.agent.DeploymentAgent.install(DeploymentAgent.java:872)[83:io.fabric8.fabric-agent:1.1.0.redhat-015]
at io.fabric8.agent.DeploymentAgent.doUpdate(DeploymentAgent.java:583)[83:io.fabric8.fabric-agent:1.1.0.redhat-015]
at io.fabric8.agent.DeploymentAgent$2.run(DeploymentAgent.java:304)[83:io.fabric8.fabric-agent:1.1.0.redhat-015]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)[:1.7.0_51]
at java.util.concurrent.FutureTask.run(FutureTask.java:262)[:1.7.0_51]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)[:1.7.0_51]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)[:1.7.0_51]
at java.lang.Thread.run(Thread.java:744)[:1.7.0_51]
Caused by: org.osgi.framework.BundleException: Unresolved constraint in bundle org.ops4j.pax.url.war [290]: Singleton conflict.
at org.apache.felix.framework.Felix.resolveBundleRevision(Felix.java:4002)[org.apache.felix.framework-4.4.1.jar:]
at org.apache.felix.framework.Felix.startBundle(Felix.java:2045)[org.apache.felix.framework-4.4.1.jar:]
at org.apache.felix.framework.BundleImpl.start(BundleImpl.java:976)[org.apache.felix.framework-4.4.1.jar:]
at org.apache.felix.framework.BundleImpl.start(BundleImpl.java:963)[org.apache.felix.framework-4.4.1.jar:]
at io.fabric8.agent.DeploymentAgent.install(DeploymentAgent.java:865)[83:io.fabric8.fabric-agent:1.1.0.redhat-015]
... 7 more