Jaxb name conflict with underscores

<xs:element name="_SortFields" nillable="true" type="tns:_SortFields"/>

will conflict with

<xs:element name="SortFields" nillable="true" type="tns:SortFields"/>

giving the error:

Two declarations cause a collision in the ObjectFactory class.
  line 300 of file:blah.xsd

(Related to above error) This is the other declaration.   
  line 385 of file:blah.xsd

because it is removing underscores from names by default.

A bindings file like this will fix it:
<jxb:bindings version="2.1" xmlns:jxb="http://java.sun.com/xml/ns/jaxb"
              xmlns:xjc="http://java.sun.com/xml/ns/jaxb/xjc"
              xmlns:jaxws="http://java.sun.com/xml/ns/jaxws" 
              xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"
              xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <jxb:globalBindings underscoreBinding="asCharInWord">
        <xjc:simple/>
        <xjc:serializable />
    </jxb:globalBindings>
</jxb:bindings>