IllegalStateException when getting external schema while creating JAX-WS client

Issue

I'm getting an IllegalStateException when trying to create a JAX-WS client:

2013-05-07 16:21:25,025 ERROR [com.redhat.Test] (processFaultMessage) Fault Message:javax.xml.ws.WebServiceException: java.lang.IllegalStateException: Cannot load grammar: https://some.address.com:4443/my/external/schema.xsd
        org.jboss.ws.core.jaxws.spi.ProviderImpl.createServiceDelegate(ProviderImpl.java:72)
        javax.xml.ws.Service.<init>(Service.java:56)
        com.redhat.Service.<init>(PassPO2Delphi_Service.java:42)
        com.redhat.Test.createJaxwsService(PassPO2DelphiClient.java:74)
        sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        java.lang.reflect.Method.invoke(Method.java:597)
        org.jboss.soa.esb.listeners.message.ActionProcessorMethodInfo.processMethods(ActionProcessorMethodInfo.java:102)
        org.jboss.soa.esb.listeners.message.OverriddenActionLifecycleProcessor.process(OverriddenActionLifecycleProcessor.java:74)
        org.jboss.soa.esb.listeners.message.ActionProcessingPipeline.processPipeline(ActionProcessingPipeline.java:649)
        org.jboss.soa.esb.listeners.message.ActionProcessingPipeline.access$000(ActionProcessingPipeline.java:84)
        org.jboss.soa.esb.listeners.message.ActionProcessingPipeline$1.run(ActionProcessingPipeline.java:1021)
        org.jboss.soa.esb.listeners.message.ActionProcessingPipeline$1.run(ActionProcessingPipeline.java:1018)
        java.security.AccessController.doPrivileged(Native Method)
        javax.security.auth.Subject.doAsPrivileged(Subject.java:454)
        org.jboss.soa.esb.listeners.message.ActionProcessingPipeline.processPipeline(ActionProcessingPipeline.java:588)
        org.jboss.soa.esb.listeners.message.ActionProcessingPipeline.process(ActionProcessingPipeline.java:433)
        org.jboss.soa.esb.listeners.message.MessageAwareListener$TransactionalRunner.run(MessageAwareListener.java:550)
        java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)