Funny thing is that it doesn't happen at startup if the SAR file is in the deploy directory. However, if I un-deploy it and then re-deploy it, the exception occurs:
[MainDeployer] Could not create deployment: file:/jboss-4.0.4RC1/server/default/tmp/deploy/tmp35861jboss-wsrp.sar-contents/jboss-wsrp.war

java.lang.IllegalArgumentException: Illegal null argument:ns
at org.jboss.ws.metadata.wsdl.xmlschema.JBossXSModel.createNamespaceItemIfNotExistent(JBossXSModel.java:504)
at org.jboss.ws.metadata.wsdl.xmlschema.JBossXSModel.addXSAnnotation(JBossXSModel.java:312)
at org.jboss.ws.metadata.wsdl.xmlschema.WSSchemaUtils.copyXSModel(WSSchemaUtils.java:664)
at org.jboss.ws.tools.JavaToXSD.parseSchema(JavaToXSD.java:206)
at org.jboss.ws.metadata.wsdl.WSDL11Reader.processTypes(WSDL11Reader.java:212)
at org.jboss.ws.metadata.wsdl.WSDL11Reader.processTypes(WSDL11Reader.java:226)
at org.jboss.ws.metadata.wsdl.WSDL11Reader.processTypes(WSDL11Reader.java:226)
at org.jboss.ws.metadata.wsdl.WSDL11Reader.process(WSDL11Reader.java:123)
at org.jboss.ws.metadata.wsdl.WSDLDefinitionsFactory.parse(WSDLDefinitionsFactory.java:140)
at org.jboss.ws.metadata.ServiceMetaData.getWsdlDefinitions(ServiceMetaData.java:253)
at org.jboss.ws.metadata.JSR109ServerMetaDataBuilder.buildMetaData(JSR109ServerMetaDataBuilder.java:110)
at org.jboss.ws.server.WebServiceDeployerJSE.createWebServicesMetaData(WebServiceDeployerJSE.java:187)
at org.jboss.ws.server.WebServiceDeployer.create(WebServiceDeployer.java:99)
at org.jboss.ws.server.WebServiceDeployerJSE.create(WebServiceDeployerJSE.java:65)
at org.jboss.deployment.SubDeployerInterceptorSupport$XMBeanInterceptor.create(SubDeployerInterceptorSupport.java:175)
at org.jboss.deployment.SubDeployerInterceptor.invoke(SubDeployerInterceptor.java:92)
at org.jboss.mx.server.Invocation.invoke(Invocation.java:88)
at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:260)
at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:190)
at $Proxy91.create(Unknown Source)
at org.jboss.deployment.MainDeployer.create(MainDeployer.java:953)
at org.jboss.deployment.MainDeployer.create(MainDeployer.java:943)
at org.jboss.deployment.MainDeployer.deploy(MainDeployer.java:807)
at org.jboss.deployment.MainDeployer.deploy(MainDeployer.java:771)
at sun.reflect.GeneratedMethodAccessor73.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:155)
at org.jboss.mx.server.Invocation.dispatch(Invocation.java:94)
at org.jboss.mx.interceptor.AbstractInterceptor.invoke(AbstractInterceptor.java:133)
at org.jboss.mx.server.Invocation.invoke(Invocation.java:88)
at org.jboss.mx.interceptor.ModelMBeanOperationInterceptor.invoke(ModelMBeanOperationInterceptor.java:142)
at org.jboss.mx.server.Invocation.invoke(Invocation.java:88)
at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:260)
at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:190)
at $Proxy8.deploy(Unknown Source)
at org.jboss.deployment.scanner.URLDeploymentScanner.deploy(URLDeploymentScanner.java:334)
at org.jboss.deployment.scanner.URLDeploymentScanner.scan(URLDeploymentScanner.java:522)
at org.jboss.deployment.scanner.AbstractDeploymentScanner$ScannerThread.doScan(AbstractDeploymentScanner.java:207)
at org.jboss.deployment.scanner.AbstractDeploymentScanner$ScannerThread.loop(AbstractDeploymentScanner.java:218)
at org.jboss.deployment.scanner.AbstractDeploymentScanner$ScannerThread.run(AbstractDeploymentScanner.java:197)