WSDL2PHP generates anonymous classes

When I generate code from the WSDL below I end up with anonymous classes in the php code. Does anyone know the reason for this or how to fix it?

Modifying the bookmark schema and changing refs attributes to name and type attributes is not an acceptable solution although it works. I've tried both versions, 2.0.0 and the latest SVN version, but none of them seems to work.

<?php

// PHP classes corresponding to the data types in defined in WSDL

class setBookmarks {

    /**
     * @var string
     */
    public $contentID;

    /**
     * @var (object)anonymous0
     */
    public $bookmarkSet;

}

class anonymous0 {

    /**
     * @var (object)anonymous1
     */
    public $title;

    /**
     * @var string
     */
    public $uid;

}

class anonymous1 {

    /**
     * @var string
     */
    public $text;

}

class setBookmarksResponse {

    /**
     * @var boolean
     */
    public $setBookmarksResult;

}

// define the class map
$class_map = array(
    "setBookmarks" => "setBookmarks",
    "anonymous0" => "anonymous0",
    "anonymous1" => "anonymous1",
    "setBookmarksResponse" => "setBookmarksResponse"); 

...

?>

WSDL

<definitions name="DAISYOnlineService" targetNamespace="http://www.daisy.org/ns/daisy-online/" xmlns="http://schemas.xmls
oap.org/wsdl/" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:tns="http://www.daisy.org/ns/daisy-online/">

    <types>
        <xs:schema targetNamespace="http://www.daisy.org/ns/daisy-online/" elementFormDefault="qualified" attributeFormDe
fault="unqualified" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:daisy="http://www.daisy.org/z3986/2005/bookmark/">

        <xs:import namespace="http://www.daisy.org/z3986/2005/bookmark/" schemaLocation="bookmark-2005-1.xsd"/>

        <xs:element name="setBookmarks">
            <xs:complexType>
                <xs:sequence>
                    <xs:element minOccurs="1" maxOccurs="1" name="contentID" type="xs:string"/>
                    <xs:element minOccurs="1" maxOccurs="1" ref="daisy:bookmarkSet"/>
                </xs:sequence>
            </xs:complexType>
        </xs:element>

        <xs:element name="setBookmarksResponse">
            <xs:complexType>
                <xs:sequence>
                    <xs:element minOccurs="1" maxOccurs="1" name="setBookmarksResult" type="xs:boolean"/>
                </xs:sequence>
            </xs:complexType>
        </xs:element>

    </xs:schema>
    </types>

    <message name="setBookmarks_inputMessage">
    <part name="parameters" element="tns:setBookmarks"/>
    </message>

    <message name="setBookmarks_outputMessage">
    <part name="parameters" element="tns:setBookmarksResponse"/>
    </message>

    <portType name="daisy-online">
        <operation name="setBookmarks">
        <input message="tns:setBookmarks_inputMessage"/>
        <output message="tns:setBookmarks_outputMessage"/>
        </operation>
    </portType>

    <binding name="DaisyOnlineService" type="tns:daisy-online">
        <soap:binding style="document" transport="http://schemas.xmlsoap.org/soap/http"/>
        <operation name="setBookmarks">
            <soap:operation soapAction="/setBookmarks" style="document"/>
            <input>
                <soap:body use="literal"/>
            </input>
            <output>
                <soap:body use="literal"/>
            </output>
        </operation>
    </binding>

    <service name="Daisy_Online_Service">
        <port name="HTTP" binding="tns:DaisyOnlineService">
            <soap:address location="http://anyURI/service.php"/>
        </port>
    </service>

</definitions>

Schema

<xs:schema id="bookmark-2005-1" xmlns="http://www.daisy.org/z3986/2005/bookmark/" targetNamespace="http://www.daisy.org/z
3986/2005/bookmark/" xmlns:xs="http://www.w3.org/2001/XMLSchema">

    <xs:element name="bookmarkSet">
        <xs:complexType>
            <xs:sequence>
                <xs:element ref="title"/>
                <xs:element ref="uid"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>

    <xs:element name="title">
        <xs:complexType>
            <xs:sequence>
                <xs:element ref="text"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>

    <xs:element name="uid" type="xs:string" />

    <xs:element name="text" type="xs:string" />

</xs:schema>