dieego_
Olá Izaura
Também passei por este problema, encontrei o seguinte exemplo na internet e deu certo.
Utilize c:forEach no lugar do a4j:repeat que dará certo:
<a4j:outputPanel id="output">
<rich:tabPanel id="tapPanel" width="700" rendered="#{not empty capitalsBean.foundCapitals}">
<c:forEach items="#{capitalsBean.foundCapitals}" var="cap">
<rich:tab name="#{cap.name}" >
<f:facet name="label">
<h:panelGrid columns="2">
<h:outputText value="#{cap.name}" />
<h:graphicImage value="/images/icons/delete.gif"
style="width:12px; height:12px;"
onclick="myFunc('#{cap.name}'); Event.stop(event);"/>
</h:panelGrid>
</f:facet>
<h:panelGrid columns="2" style="margin:20">
<h:outputText value="State Name" />
<h:inputText value="#{cap.state}" />
<h:outputText value="State Capital" />
<h:inputText value="#{cap.name}" />
<h:outputText value="State TimeZone" />
<h:inputText value="#{cap.timeZone}" />
</h:panelGrid>
</rich:tab>
</c:forEach>
</rich:tabPanel>
<h:outputText value="No active search results."
style="font-style:italic" rendered="#{empty capitalsBean.foundCapitals}"/>
</a4j:outputPanel>
ahh… não esqueça de incluir a taglib (xmlns:c=“http://java.sun.com/jstl/core”)