Collection validation with hibernate annotation @Size doesn't work

[derkd]

Hi all,
I have a collection which I bind to my rich faces datalist. I want to display a message if the collection has a size bigger than 10. I also want to display a message when it does not have any items in it.
How do I display different messages for both?
I now don't even get any message... What am I doing wrong?

I'm using Seam 1.2.1 with richfaces and hibernate validator 3.0.0. and CXF as webservice. I don't use a database, I only use hibernate validator. I managed to get this work with @Length on a string but now looking for a collection size.

@Size(max=5, message="#{messages['maxOpleidingenList.length']}")
     public List<IOpleiding> getLettercombinatieOpleidingen() {
          return lettercombinatieOpleidingen;
     }

my page looks like this:

<s:validateAll>
<s:decorate id="idBeroepLettercombBeroep"> 
                  <s:message/> 
                     <rich:dataList id="lettercombBeroep" var="_beroep" value="#{lettercombinatieBeroepen}">
                     
                          <a4j:commandLink id="beroep" action="#{zoekBeroepAction.retrieveBeroepRelatie(_beroep)}" oncomplete="registreer('#{zoekBeroepAction.beroepRelaties.cdBeroepsnaam}+#{zoekBeroepAction.beroepRelaties.omsBeroepsnaam}+#{_beroep.cdBeroepsnaam}+#{_beroep.omsBeroepsnaam}')">#{_beroep.omsBeroepsnaam}</a4j:commandLink>
                          <h:outputText id="whiteSpace" value="   "/>
                          <a4j:commandLink id="beroepInfoLink" action="#{zoekBeroepAction.retrieveBeroepRelatie(_beroep)}" 
                          oncomplete="Richfaces.showModalPanel('informationLettercombinatieBeroepPanel');" 
                          reRender="selectedLettercombinatieBeroep" eventsQueue="beroepLetterQueue" ignoreDupResponses="true">
                              <h:graphicImage id="information" style="border-width:0" value="../images/I.png" />
                         </a4j:commandLink>
                    </rich:dataList>
                    </s:decorate>
</s:validateAll>