t:collapsiblePanel doesn't work inside a t:panelTabbedPane and a s:subform.

The collapsiblePanel doesn't work inside a t:panelTabbedPane and a s:subform. Collapse isn't executed.
If the collapsiblePanel is defined outside the subForm, it works fine

— this DOESN't work ----
<h:form>
<t:panelTabbedPane serverSideTabSwitch="true">
<t:panelTab label="myTab">
<s:subForm>
<t:collapsiblePanel id="collapsePanelPhone"
value="#

{myBean.phoneCollapsed}"
var="phonePanelCollapsed">

<f:facet name="header">
<t:div id="xyz">
<t:headerLink immediate="true"
actionListener="#{myBean.changePhoneCollapsed}">
<h:outputText value="collapsedYes"
rendered="#{phonePanelCollapsed}" />
<h:outputText value="collapsedNo"
rendered="#{!phonePanelCollapsed}" />
</t:headerLink>
<t:panelGroup rendered="#{!phonePanelCollapsed}">
<h:outputText value="openContent" />
<h:inputText value="openContent_2" />
<h:outputText value="openContent_33" />
</t:panelGroup>
<f:facet name="closedContent">
<h:outputText value="closedContent" />
</f:facet>
</t:div>
</f:facet>
</t:collapsiblePanel>
</s:subForm>
</t:panelTab>
...




— this works fine —
<h:form>
<t:panelTabbedPane serverSideTabSwitch="true">
<t:panelTab label="myTab">
<t:collapsiblePanel id="collapsePanelPhone"
value="#{myBean.phoneCollapsed}

"
var="phonePanelCollapsed">

<f:facet name="header">
<t:div id="xyz">
<t:headerLink immediate="true"
actionListener="#

{myBean.changePhoneCollapsed}

">
<h:outputText value="collapsedYes"
rendered="#

{phonePanelCollapsed}

" />
<h:outputText value="collapsedNo"
rendered="#

{!phonePanelCollapsed}" />
</t:headerLink>
<t:panelGroup rendered="#{!phonePanelCollapsed}

">
<h:outputText value="openContent" />
<h:inputText value="openContent_2" />
<h:outputText value="openContent_33" />
</t:panelGroup>
<f:facet name="closedContent">
<h:outputText value="closedContent" />
</f:facet>
</t:div>
</f:facet>
</t:collapsiblePanel>
...

any suggestions
thx, bruno