Why does this work?:

Version 1:

<h:panelGroup>

        <h:form prependId="false">

                    <ul>

                        <a4j:repeat var="_t" value="#{bean.list}">

                            <li><a4j:commandLink action="#{bean.action(_t)}" render=":c1" value="#{_t}" execute="@this"/></li>

                        </a4j:repeat>

                    </ul>

                </ui:repeat>

        </h:form>

</h:panelGroup>

and ths not:

Version 2:

<h:panelGroup>

        <h:form prependId="false">

                    <ul>

                        <ui:repeat var="_t" value="#{bean.list}">

                            <li><a4j:commandLink action="#{bean.action(_t)}" render=":c1" value="#{_t}" execute="@this"/></li>

                        </ui:repeat>

                    </ul>

                </ui:repeat>

        </h:form>

</h:panelGroup>

When clicking commandLink in version 2, then no action is fired.

When clicking commandLink in version 1, then action is fired as expected.

Why does version 2 not work?