Camel route using spring-ws client occasionally th

I have a camel 'seda' route that contains code roughly:

JaxbDataFormat jaxb = new JaxbDataFormat(false);
jaxb.setContextPath("com.example.data.api");

from("seda:validate")
   .marshal(jaxb)
   .to("spring-ws:" + getDataServiceURL())
   .unmarshal(jaxb)

I send an object from com.example.data.api, the JaxbDataFormat formatter sets it up as a SOAP request and passes it along wo spring-ws to actually send to my service. This works like a charm most of the time.

I say "most" because every now and then, spring-ws throws an exception like so:

org.springframework.ws.client.WebServiceTransformerException: Transformation error: Can't transform a Source of type javax.xml.transform.stax.StAXSource; nested exception is javax.xml.transform.TransformerException: Can't transform a Source of type javax.xml.transform.stax.StAXSource
    at org.springframework.ws.client.core.WebServiceTemplate.doSendAndReceive(WebServiceTemplate.java:608)
    at org.springframework.ws.client.core.WebServiceTemplate.sendAndReceive(WebServiceTemplate.java:537)
    at org.springframework.ws.client.core.WebServiceTemplate.doSendAndReceive(WebServiceTemplate.java:492)
    at org.springframework.ws.client.core.WebServiceTemplate.sendSourceAndReceive(WebServiceTemplate.java:479)
    at org.springframework.ws.client.core.WebServiceTemplate.sendSourceAndReceive(WebServiceTemplate.java:470)
    at org.apache.camel.component.spring.ws.SpringWebserviceProducer.process(SpringWebserviceProducer.java:81)
    at org.apache.camel.util.AsyncProcessorConverterHelper$ProcessorToAsyncProcessorBridge.process(AsyncProcessorConverterHelper.java:61)
    at org.apache.camel.util.AsyncProcessorHelper.process(AsyncProcessorHelper.java:73)

The core of that is this error message: "Can't transform a Source of type javax.xml.transform.stax.StAXSource".

None of that makes sense. The Jaxb marshalling will have already made sure that the object in question is an XML string (according to any debug logging I do). Furthermore, this exact code works most of the time and only occasionally will fail. It appears random.

For instance, I ran a test just a few minutes ago where I sent a message into my route and got this error. I then restarted my service and resend the exact same message... and it worked like a charm. Same code; same environment; same test -- two different results.

It's this randomness that makes this so maddening. Any ideas what I should be looking for to making sure this never happens?

The issue is not with Camel but Spring-WS. Modifying the transformerFactoryClass in WS template config would work

<bean id="baseCamelMarshallerWSTemplate" class="org.springframework.ws.client.core.WebServiceTemplate" scope="prototype">
        <constructor-arg ref="messageFactory" />
        <property name="messageSender">
            <ref bean="httpSender"/>
        </property>
        <property name="checkConnectionForError" value="true"/>
        **<property name="transformerFactoryClass" value="com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl"/>**
    </bean>

If you still face the issue, please share spring WS config and a test case