web services - NAMESPACE_ERR using ws client grails plugin -

i'm new using web services , i'm trying develop client 3th party web service using ws client plugin. tried example in documentation , worked fine, when try use said web services following exception

| error 2013-05-06 11:03:22,853 [http-bio-8080-exec-1] error errors.grailsexceptionresolver  - domexception occurred when processing request: [get] /webgains/webgains/index namespace_err: attempt made create or change object in way incorrect regard namespaces.. stacktrace follows: message: namespace_err: attempt made create or change object in way incorrect regard namespaces.     line | method ->> 2530 | checkdomnserr                      in com.sun.org.apache.xerces.internal.dom.coredocumentimpl - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  |    117 | setname                            in com.sun.org.apache.xerces.internal.dom.attrnsimpl |     78 | <init> . . . . . . . . . . . . . . in     '' |   2142 | createattributens                  in com.sun.org.apache.xerces.internal.dom.coredocumentimpl |    659 | setattributens . . . . . . . . . . in com.sun.org.apache.xerces.internal.dom.elementimpl |    470 | serializeattribute                 in org.apache.ws.commons.schema.xmlschemaserializer |    832 | serializecomplexcontentrestriction in     '' |    682 | serializecomplexcontent            in     '' |    903 | serializecomplextype . . . . . . . in     '' |   2400 | serializeschemachild               in     '' |   1659 | serializeschemaelement . . . . . . in     '' |    132 | serializeschema                    in     '' |    478 | addschemas . . . . . . . . . . . . in org.apache.cxf.endpoint.dynamic.dynamicclientfactory |    316 | createclient                       in     '' |    235 | createclient . . . . . . . . . . . in     '' |    214 | createclient                       in     '' |    198 | createclient . . . . . . . . . . . in groovyx.net.ws.abstractcxfwsclient |    107 | initialize                         in groovyx.net.ws.wsclient |     19 | getclient . . . . . . . . . . . .  in org.grails.plugins.wsclient.service.webservice |     10 | index                              in webgains.webgainscontroller |    195 | dofilter . . . . . . . . . . . . . in grails.plugin.cache.web.filter.pagefragmentcachingfilter |     63 | dofilter                           in grails.plugin.cache.web.filter.abstractfilter |   1110 | runworker . . . . . . . . . . . .  in java.util.concurrent.threadpoolexecutor |    603 | run                                in java.util.concurrent.threadpoolexecutor$worker ^    722 | run . . . . . . . . . . . . . . .  in java.lang.thread 

i around bit , found cases adding xalan-2.7.0.jar solves problem. tried , still dont work.

any ideas?

edit:

i'm using following code:

def wsdlurl = "http://ws.webgains.com/aws.php" def proxy = webservice.getclient(wsdlurl)  def result = proxy.getfullupdatedearnings(new gregoriancalendar(),new gregoriancalendar(),1,"a","b") 

the exception thrown in webservice.getclient(wsdlurl)