Nullpointer exception while publishing to eap-5.1 (probably only when using compressed archives)

I got nullpointer exception while publishing seam-ear project to eap-5.1:

java.lang.NullPointerException
at org.eclipse.wst.common.componentcore.internal.flat.VirtualComponentFlattenUtility.addMembersInternal(VirtualComponentFlattenUtility.java:88)
at org.eclipse.wst.common.componentcore.internal.flat.VirtualComponentFlattenUtility.addMembers(VirtualComponentFlattenUtility.java:50)
at org.eclipse.wst.common.componentcore.internal.flat.FlatVirtualComponent.treeWalk(FlatVirtualComponent.java:163)
at org.eclipse.wst.common.componentcore.internal.flat.FlatVirtualComponent.cacheResources(FlatVirtualComponent.java:121)
at org.eclipse.wst.common.componentcore.internal.flat.FlatVirtualComponent.getChildModules(FlatVirtualComponent.java:111)
at org.eclipse.wst.web.internal.deployables.FlatComponentDeployable.getURI(FlatComponentDeployable.java:220)
at org.jboss.ide.eclipse.as.core.publishers.PublishUtil.getParentRelativeURI(PublishUtil.java:165)
at org.jboss.ide.eclipse.as.core.publishers.PublishUtil.getDeployPath(PublishUtil.java:155)
at org.jboss.ide.eclipse.archives.webtools.modules.LocalZippedPublisherUtil.getOutputFilePath(LocalZippedPublisherUtil.java:308)
at org.jboss.ide.eclipse.archives.webtools.modules.LocalZippedPublisherUtil.fullPublish(LocalZippedPublisherUtil.java:198)
at org.jboss.ide.eclipse.archives.webtools.modules.LocalZippedPublisherUtil.handleChildrenDeltas(LocalZippedPublisherUtil.java:122)
at org.jboss.ide.eclipse.archives.webtools.modules.LocalZippedPublisherUtil.handleChildrenDeltas(LocalZippedPublisherUtil.java:135)
at org.jboss.ide.eclipse.archives.webtools.modules.LocalZippedPublisherUtil.publishModule(LocalZippedPublisherUtil.java:75)
at org.jboss.ide.eclipse.archives.webtools.modules.WTPZippedPublisher.publishModule(WTPZippedPublisher.java:71)
at org.jboss.ide.eclipse.as.core.publishers.AbstractPublishMethod.publishModule(AbstractPublishMethod.java:77)
at org.jboss.ide.eclipse.as.core.server.internal.DeployableServerBehavior.publishModule(DeployableServerBehavior.java:67)
at org.eclipse.wst.server.core.model.ServerBehaviourDelegate.publishModule(ServerBehaviourDelegate.java:1025)
at org.eclipse.wst.server.core.model.ServerBehaviourDelegate.publishModules(ServerBehaviourDelegate.java:1115)
at org.eclipse.wst.server.core.model.ServerBehaviourDelegate.publish(ServerBehaviourDelegate.java:948)
at org.eclipse.wst.server.core.model.ServerBehaviourDelegate.publish(ServerBehaviourDelegate.java:775)
at org.eclipse.wst.server.core.internal.Server.publishImpl(Server.java:2889)
at org.eclipse.wst.server.core.internal.Server$PublishJob.run(Server.java:337)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)

Will try to isolate / provide steps to reproduce.