I have a object named Praca, defined in this hbm file

<?xml version="1.0" encoding="utf-8" ?>

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
namespace="ProducaoMidiaMix.Negocio" assembly="ProducaoMidiaMix">

<class name="IbopePraca" table="IBOPE_PRACA_UNIDADE">

<composite-id name="IbopePracakey" class="ProducaoMidiaMix.Negocio.IbopePraca+IbopePracaKey, ProducaoMidiaMix" unsaved-value="none" access="property">
<key-property name="CodigoUnidadeNegocio" type="System.Int32" column="COD_UNIDADE_NEGOCIO" />
<key-property name="CodigoPraca" type="System.Int32" column="COD_PRACA" />
</composite-id>


<property name="NomePraca" type="System.String" column="NOME_PRACA_UNIDADE" not-null="true" />
<property name="CodigoRegiao" type="System.Int32" column="COD_REGIAO" not-null="true" />
<property name="Integration" type="System.Int16" column="INTEGRATION" not-null="false" />


<bag name="ConfiguracaoPraca" inverse="true" lazy="true" cascade="all" >
<key>
<column name="COD_UNIDADE_NEGOCIO" not-null="true" />
<column name="COD_PRACA" not-null="true" />
</key>
<one-to-many class="ProducaoMidiaMix.Negocio.ConfiguracaoPraca, ProducaoMidiaMix" />

<filter name="ConfiguracaoIbopePracaAtual"
condition=":dataConfiguracaoPraca BETWEEN CONFIGPRACA_DATAINICIO and CONFIGPRACA_DATAFIM"/>
</bag>

<bag name="Estimativa" inverse="true" lazy="true" cascade="none">
<key>
<column name="COD_PRACA" not-null="true" />
<column name="COD_UNIDADE_NEGOCIO" not-null="true" />
</key>
<one-to-many class="ProducaoMidiaMix.Negocio.Estimativa, ProducaoMidiaMix" />
</bag>

<bag name="EmissoraUnidade" inverse="true" lazy="true" cascade="none">
<key>
<column name="COD_PRACA" not-null="true" />
<column name="COD_UNIDADE_NEGOCIO" not-null="true" />
</key>
<one-to-many class="ProducaoMidiaMix.Negocio.EmissoraUnidade, ProducaoMidiaMix" />
</bag>

<filter name="UnidadeNegocioAudiencia"
condition="COD_UNIDADE_NEGOCIO = 2"/>

</class>

<filter-def name="UnidadeNegocioAudiencia">
</filter-def>

<filter-def name="ConfiguracaoIbopePracaAtual">
<filter-param name="dataConfiguracaoPraca" type="date"/>
</filter-def>

</hibernate-mapping>

when i execute the command line :

ibopePracaList = session.CreateQuery("from IbopePraca as ibopePraca order by ibopePraca.NomePraca").List<IbopePraca>();

I get the values of the ibopePraca and the return values of the bag configuracaoPraca, but the values of "estimativa" and "EmissoraUnidade" is null, why is this happing? is something wrong in my configuration?

here is the hbm files for the objects "ConfiguracaoPraca", "Estimativa" and "EmissoraUnidade"

---------------------------------------------------------------------------
<?xml version="1.0" encoding="utf-8" ?>



<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
namespace="ProducaoMidiaMix.Negocio" assembly="ProducaoMidiaMix">


<class name="ConfiguracaoPraca" table="SPMM_CONFIGURACAOPRACA">


<composite-id name="ConfiguracaoPracakey" class="ProducaoMidiaMix.Negocio.ConfiguracaoPraca+ConfiguracaoPracaKey, ProducaoMidiaMix" unsaved-value="none" access="property">
<key-property name="CodigoConfiguracaoPraca" type="System.Int32" column="CONFIGPRACA_COD" />
<key-property name="DataInicio" type="System.DateTime" column="CONFIGPRACA_DATAINICIO" />
</composite-id>


<property name="QuantidadeEntrevistas" type="System.Int32" column="CONFIGPRACA_QTDENTREVISTA" not-null="true" />
<property name="DiretorioEntrada" type="System.String" column="CONFIGPRACA_DIRETORIOARQUIVOCOLETA" not-null="true" />
<property name="DiretorioTemporario" type="System.String" column="CONFIGPRACA_DIRETORIOARQUIVOTEMPORARIO" not-null="true" />
<property name="DiretorioSaida" type="System.String" column="CONFIGPRACA_DIRETORIORESULTADO" not-null="true" />
<property name="Usuario" type="System.String" column="USUARIO_NOME" not-null="true" length="100" />
<property name="DataFim" type="System.DateTime" column="CONFIGPRACA_DATAFIM" not-null="true" />


<many-to-one name="IbopePraca" class="ProducaoMidiaMix.Negocio.IbopePraca, ProducaoMidiaMix" fetch="select">
<column name="COD_UNIDADE_NEGOCIO" not-null="true" />
<column name="COD_PRACA" not-null="true" />
</many-to-one>


<bag name="ListaTarefa" inverse="true" lazy="true" cascade="none">
<key>
<column name="CONFIGPRACA_COD" not-null="true" />
<column name="CONFIGPRACA_DATAINICIO" not-null="true" />
</key>
<one-to-many class="ProducaoMidiaMix.Negocio.Tarefa, ProducaoMidiaMix" />
</bag>

<filter name="ConfiguracaoPracaAtual"
condition=":dataConfiguracaoPraca BETWEEN CONFIGPRACA_DATAINICIO and CONFIGPRACA_DATAFIM"/>


</class>

<filter-def name="ConfiguracaoPracaAtual">
<filter-param name="dataConfiguracaoPraca" type="date"/>
</filter-def>

</hibernate-mapping>

---------------------------------------------------------------------------
<hibernate-mapping default-cascade="none" xmlns="urn:nhibernate-mapping-2.2">
<class name="ProducaoMidiaMix.Negocio.Estimativa, ProducaoMidiaMix" table="SPMM_ESTIMATIVA">
<composite-id name="Estimativakey" class="ProducaoMidiaMix.Negocio.Estimativa+EstimativaKey, ProducaoMidiaMix" unsaved-value="none" access="property">
<key-property name="DataInicio" type="System.DateTime" column="ESTIMATIVA_DATAINICIAL" />
<key-many-to-one name="Target" class="ProducaoMidiaMix.Negocio.Target, ProducaoMidiaMix" >
<column name="TARGET_COD" />
<column name="TARGET_DATAINICIO" />
</key-many-to-one>
<key-many-to-one name="IbopePraca" class="ProducaoMidiaMix.Negocio.IbopePraca, ProducaoMidiaMix">
<column name="COD_UNIDADE_NEGOCIO" />
<column name="COD_PRACA" />
</key-many-to-one>
</composite-id>
<property name="DataFim" type="System.DateTime" column="ESTIAMTIVA_DATAFINAL" not-null="false" />
<property name="Valor" type="System.Int32" column="ESTIMATIVA_VALOR" not-null="false" />
<property name="Usuario" type="System.String" column="USUARIO_NOME" not-null="true" length="100" />

<filter name="EstimativaAtual"
condition=":dataEstimativa BETWEEN ESTIMATIVA_DATAINICIAL and ESTIAMTIVA_DATAFINAL"/>
</class>

<filter-def name="EstimativaAtual">
<filter-param name="dataEstimativa" type="date"/>
</filter-def>

</hibernate-mapping>
---------------------------------------------------------------------------
<hibernate-mapping default-cascade="none" xmlns="urn:nhibernate-mapping-2.2">
<class name="ProducaoMidiaMix.Negocio.EmissoraUnidade, ProducaoMidiaMix" table="SUM_RD_EMISSORA_UNIDADE">
<composite-id name="EmissoraUnidadekey" class="ProducaoMidiaMix.Negocio.EmissoraUnidade+EmissoraUnidadeKey, ProducaoMidiaMix" unsaved-value="none" access="property">
<key-property name="DataInicio" type="System.DateTime" column="DATAINI_UNIDADE" />
<key-many-to-one name="Emissora" class="ProducaoMidiaMix.Negocio.Emissora, ProducaoMidiaMix">
<column name="COD_EMISSORA" />
<column name="COD_PRACA" />
<column name="DATAINI_EMISSORA" />
</key-many-to-one>
<key-many-to-one name="IbopePraca" class="ProducaoMidiaMix.Negocio.IbopePraca, ProducaoMidiaMix">
<column name="COD_PRACA" />
<column name="COD_UNIDADE_NEGOCIO" />
</key-many-to-one>
</composite-id>
<property name="NomeEmissoraUnidade" type="System.String" column="NOME_EMISSORA_UNIDADE" not-null="true" length="30" />
<property name="DataFim" type="System.DateTime" column="DATAFIM_UNIDADE" not-null="true" />
<property name="Abreviatura3" type="System.String" column="ABR3_UNIDADE" not-null="false" length="3" />
</class>
</hibernate-mapping>
------------------------------------------------------------------------------

Please, someone can help in find a solution to when load the object IbopePraca, i get the values of the Estimativa and EmissoraUnidade?

[]´s