Weld conversation crash when used in portlet

When attempting to view a JSF2/Weld based portlet in a portal the following exception is thrown:

14:11:54,917 ERROR [render_portlet_jsp:154] java.lang.IllegalStateException: Must call associate() before calling activate()
at org.jboss.weld.context.AbstractConversationContext.activate(AbstractConversationContext.java:200)
at org.jboss.weld.jsf.WeldPhaseListener.activateConversations(WeldPhaseListener.java:108)
at org.jboss.weld.jsf.WeldPhaseListener.beforePhase(WeldPhaseListener.java:85)
at com.sun.faces.lifecycle.Phase.handleBeforePhase(Phase.java:228)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:99)
at com.sun.faces.lifecycle.RestoreViewPhase.doPhase(RestoreViewPhase.java:116)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
at org.portletfaces.bridge.BridgeImpl.doFacesRequest(BridgeImpl.java:391)
at org.portletfaces.bridge.GenericFacesPortlet.doView(GenericFacesPortlet.java:181)
at javax.portlet.GenericPortlet.doDispatch(GenericPortlet.java:328)
at javax.portlet.GenericPortlet.render(GenericPortlet.java:233)
at com.liferay.portlet.FilterChainImpl.doFilter(FilterChainImpl.java:100)
at com.liferay.portal.kernel.portlet.PortletFilterUtil.doFilter(PortletFilterUtil.java:64)
at com.liferay.portal.kernel.servlet.PortletServlet.service(PortletServlet.java:93)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:72)
at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilter.doFilter(InvokerFilter.java:70)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)

This happens on viewing a page which starts a conversation. I'll try and attach a little example app to aid reproducing the problem.