I am having this same issue under JBoss 4.0.5.GA which should have the fix in it. Trouble is that when I reduce the scope to something I can post on here it works. When I have the full WSDL (which works under 4.0.4.GA) I get the same "... Failed to find read method or field for property '_value' ..." I check the JAXRPC (we are using wscompile) generated class and it has a "value" attribute not a "_value" attribute.

The element is question looks like:

<xsd:simpleType name="Status">

<xsd:enumeration value="InWork"/>
<xsd:enumeration value="Successful"/>
<xsd:enumeration value="Failed"/>
</xsd:restriction>
</xsd:simpleType>

So any thoughts?