ClassCastException when enabling MTOM

[Julien HENRY]

Hi everybody,

When I try to enable MTOM for handling big attachments, I receive the following 
error when using the generated client stub:

java.lang.ClassCastException: 
org.apache.axiom.om.util.OMXMLStreamReaderValidator cannot be cast to 
org.apache.axiom.om.impl.llom.OMStAXWrapper
    at 
com.xxx.vaultwebservice.client.Vault_WebServiceStub$XXXBundleType$Factory.parse(Vault_WebServiceStub.java:21236)
    at 
com.xxx.vaultwebservice.client.Vault_WebServiceStub$DownloadXXXResponse$Factory.parse(Vault_WebServiceStub.java:56454)
    at 
com.xxx.vaultwebservice.client.Vault_WebServiceStub.fromOM(Vault_WebServiceStub.java:64390)

I'm using Axis2 1.4.1 with following Maven dependencies:

       <dependency>
            <groupId>org.apache.axis2</groupId>
            <artifactId>axis2-kernel</artifactId>
            <version>1.4.1</version>
        </dependency>
        <dependency>
            <groupId>org.apache.axis2</groupId>
            <artifactId>axis2-adb</artifactId>
            <version>1.4.1</version>
        </dependency>
        <dependency>
            <groupId>org.apache.ws.commons.axiom</groupId>
            <artifactId>axiom-api</artifactId>
            <version>1.2.8</version>
        </dependency>
        <dependency>
            <groupId>org.apache.ws.commons.axiom</groupId>
            <artifactId>axiom-impl</artifactId>
            <version>1.2.8</version>
        </dependency>
        <dependency>
            <groupId>wsdl4j</groupId>
            <artifactId>wsdl4j</artifactId>
            <version>1.6.2</version>
        </dependency>

Any idea of what is the issue?

Thanks

Julien