spring MapFactoryBean return map of map instead of creating map

I would like to do map inside map using spring beans in xml i am doing the next : my goal is to have Map> mobileMap but i get wrapper that when i use mobileMap.get("mobileMap") i get the requested without the wrapper this is my xml :

<bean class="org.springframework.beans.factory.config.MapFactoryBean"
        id="mobileMap1111">
         <property name="targetMapClass">
            <value>java.util.HashMap</value>
        </property> 
        <property name="sourceMap">
            <map>
                <entry key="CFNetwork/221.5">
                    <bean class="org.springframework.beans.factory.config.MapFactoryBean">
                        <property name="targetMapClass">
                            <value>java.util.HashMap</value>
                        </property>
                        <property name="sourceMap">
                            <map>
                                <entry key="9.2.0">
                                    <bean class="com.betamedia.tp.api.model.UserAgentInfo">
                                        <property name="browser" value="Darwin" />
                                        <property name="isMobile" value="true" />
                                        <property name="browserVersion" value="9.2.0" />
                                        <property name="operatingSystem" value="Mac OS X " />
                                        <property name="operatingSystemVersion" value="10.5.2" />
                                    </bean>
                                </entry>
                            </map>
                        </property>
                    </bean>
                </entry>
                <entry key="CFNetwork/596.4.3">
                    <bean class="org.springframework.beans.factory.config.MapFactoryBean">
                        <property name="targetMapClass">
                            <value>java.util.HashMap</value>
                        </property>
                        <property name="sourceMap">
                            <map>
                                <entry key="12.4.0">
                                    <bean class="com.betamedia.tp.api.model.UserAgentInfo">
                                        <property name="browser" value="Darwin" />
                                        <property name="isMobile" value="true" />
                                        <property name="browserVersion" value="12.4.0" />
                                        <property name="operatingSystem" value="Mac OS X " />
                                        <property name="operatingSystemVersion" value="10.8.4" />
                                    </bean>
                                </entry>
                            </map>
                        </property>
                    </bean>
                </entry>


            </map>
        </property>
    </bean>

but i keep on getting in autuwired field : map of map of map and have to do :

@Autowired
    protected Map<String, Map<String, Map<String, UserAgentInfo>>> mobileMap;

instead of

@Autowired
    protected  Map<String, Map<String, UserAgentInfo>> mobileMap;

what am i doing wrong