To reproduce this issue:
1. wsgen -cp . wstest.FaultImpl against the following java file, please note, the issue will happen either when createSOAPFaultException or createSOAP12FaultException :
package wstest;

import javax.jws.WebMethod;
import javax.jws.WebService;
import javax.xml.namespace.QName;
import javax.xml.soap.Detail;
import javax.xml.soap.DetailEntry;
import javax.xml.soap.Name;
import javax.xml.soap.SOAPConstants;
import javax.xml.soap.SOAPElement;
import javax.xml.soap.SOAPException;
import javax.xml.soap.SOAPFactory;
import javax.xml.soap.SOAPFault;
import javax.xml.ws.soap.SOAPFaultException;

@WebService
public class FaultImpl {
    @WebMethod
    public void test() throws SOAPException {
        throw createSOAPFaultException();
        // throw createSOAP12FaultException(null, "SOAPFaultException");
    }

    private SOAPFaultException createSOAPFaultException() throws SOAPException {

        String namespace = "http://faultservice.org/wsdl";
        SOAPFactory soapFactory = SOAPFactory.newInstance();
        Name name = soapFactory.createName("BasicFault", "ns0", namespace);
        Detail detail = soapFactory.createDetail();
        DetailEntry entry = detail.addDetailEntry(name);
        entry.addNamespaceDeclaration("ns0", namespace);
        entry.setEncodingStyle("http://schemas.xmlsoap.org/soap/encoding/");
        entry.addNamespaceDeclaration("myenv", "http://schemas.xmlsoap.org/soap/envelope/");
        entry.addNamespaceDeclaration("myns", "http://myurri/tmp");
        Name attrName = soapFactory.createName("encodingStyle", "myenv",
                "http://schemas.xmlsoap.org/soap/envelope/");
        entry.addAttribute(attrName, "http://schemas.xmlsoap.org/soap/encoding/");
        Name attrName2 = soapFactory.createName("myAttr", "myns", "http://myurri/tmp");
        entry.addAttribute(attrName2, "myvalue");
        SOAPElement child = entry.addChildElement("message");
        child.addTextNode("basic fault");

        Name name2 = soapFactory.createName("AdditionalElement", "ns0", namespace);
        DetailEntry entry2 = detail.addDetailEntry(name2);
        entry2.addNamespaceDeclaration("ns0", namespace);

        SOAPElement child2 = entry2.addChildElement("BOGUS");
        child2.addTextNode("2 text");

        QName qname = new QName("http://schemas.xmlsoap.org/soap/envelope/", "client");
        // printDetail(detail);
        SOAPFault sf = soapFactory.createFault("soap fault exception fault", qname);
        org.w3c.dom.Node n = sf.getOwnerDocument().importNode(detail, true);
        sf.appendChild(n);
        return new SOAPFaultException(sf);

    }

    private SOAPFaultException createSOAP12FaultException(QName subcode, String msg)
            throws SOAPException {

        String namespace = "http://faultservice.org/wsdl";
        SOAPFactory soapFactory = SOAPFactory.newInstance(SOAPConstants.SOAP_1_2_PROTOCOL);
        Name name = soapFactory.createName("BasicFault", "ns0", namespace);
        Detail detail = soapFactory.createDetail();
        DetailEntry entry = detail.addDetailEntry(name);
        entry.addNamespaceDeclaration("ns0", namespace);
        entry.setEncodingStyle("http://schemas.xmlsoap.org/soap/encoding/");
        entry.addNamespaceDeclaration("myenv", "http://schemas.xmlsoap.org/soap/envelope/");
        entry.addNamespaceDeclaration("myns", "http://myurri/tmp");
        Name attrName = soapFactory.createName("encodingStyle", "myenv",
                "http://schemas.xmlsoap.org/soap/envelope/");
        entry.addAttribute(attrName, "http://schemas.xmlsoap.org/soap/encoding/");
        Name attrName2 = soapFactory.createName("myAttr", "myns", "http://myurri/tmp");
        entry.addAttribute(attrName2, "myvalue");
        SOAPElement child = entry.addChildElement("message");
        child.addTextNode("basic fault");

        Name name2 = soapFactory.createName("AdditionalElement", "ns0", namespace);
        DetailEntry entry2 = detail.addDetailEntry(name2);
        entry2.addNamespaceDeclaration("ns0", namespace);

        SOAPElement child2 = entry2.addChildElement("BOGUS");
        child2.addTextNode("2 text");

        QName qname = new QName("http://www.w3.org/2003/05/soap-envelope", "Sender");
        // printDetail(detail);
        SOAPFault sf = soapFactory.createFault(msg, qname);
        if (subcode != null)
            sf.appendFaultSubcode(subcode);
        // Node n = sf.addDetail().getOwnerDocument().importNode(detail, true);
        org.w3c.dom.Node n = sf.getOwnerDocument().importNode(detail, true);
        // printDetail((Detail)n);
        sf.appendChild(n);
        return new SOAPFaultException(sf);

    }
}

2. start the web service with the following java file:
package wstest;

 import javax.xml.ws.Endpoint;

 public class FaultService {
     public static void main(String[] args) {
         Endpoint.publish("http://localhost:8080/WebServices/faultimpl", new FaultImpl());
     }
 }

3. generate the client:
wsimport -keep -p wstest.server http://localhost:8080/WebServices/faultimpl?wsdl

4. run the client test with the following java file:
import java.rmi.*;
import javax.naming.*;
import wstest.server.*;

public class FaultClient {
    public static void main(String[] args) throws java.lang.Exception {
        FaultImplService service = new FaultImplService();
        FaultImpl port = service.getPort(FaultImpl.class);
        port.test();
    }
}

Expect Client received "SOAP Fault from server: soap fault exception fault", but actually Client received "SOAP Fault from server: Cannot find SOAP wrapper for element [ns0:BasicFault: null]"