jsf 2 - <p:selectOneRadio> is not working within <p:rowExpansion> -

i facing problem of using <p:selectoneradio> within <p:rowexpansion>.

in application have <p:datatable>, in <p:rowexpansion> have <p:datatable> row contains <p:selectoneradio>. <p:selectoneradio> doesn't alwayes show properly. instead of <p:selectoneradio> if use <h:outputtext> remaining value attribute same <p:selectoneradio> value displays properly.

.xhtml code snippet given below:

<p:datatable id="activitytable" value="#{activitydatamodel}"     var="activity" lazy="true" paginator="true"     paginatorposition="bottom" rows="10" rowsperpagetemplate="10,25,50,75"     styleclass="activitytable" widgetvar="activitydatatable" >     <p:column id="rowtoggle" styleclass="rowtoggle">         <p:rowtoggler />     </p:column>     <!--   columns   -->     <p:rowexpansion>             <p:row>                 <p:column>                     <p:datatable id="userdatalist" value="#{activity.activityuserswithactivitymanagers}"                         var="user" styleclass="hide-column-names" type="ordered" rowindexvar="rowindex">                             <p:column>                                 <h:outputtext value="#{rowindex + 1}. #{user.firstname}/>                             </p:column>                             <p:column>                                 <p:selectoneradio id="roleradio" value="#{user.activityspecificrole}">                                     <f:selectitem itemvalue="user" itemlabel="user" />                                     <f:selectitem itemvalue="manager" itemlabel="manager" />                                 </p:selectoneradio>                             </p:column>                     </p:datatable>                 </p:column>             </p:row>     </p:rowexpansion> </p:datatable> 

if use
<p:column>
<h:outputtext value="#{user.activityspecificrole}" />
</p:column>

instead of <p:selectoneradio> displays correct text. using pf-3.4+ mojarra(2.0). can tell me doing wrong?? thanks.