selectOneMenu: Value will not be set

I've got a dropdown menu, which gets the persons from our LDAP server. What I basically did was copying the SelectOneMenuDemo from the Demo files.

However, it's displaying all persons correctly in the dropdown, but it won't set the selected person to my data.manager.

This is the code from the demo:

<p:selectonemenu value="#{data.selectedPerson}" converter="ivy.ListItem">
<f:selectitem itemlabel="Select One" itemvalue=""/>
<f:selectitems value="#{data.persons}" var="it" itemvalue="#{it}" itemlabel="#{it.name}"></f:selectitems> <f:selectitems value="#{data.morePersons}" var="it" itemvalue="#{it}" itemlabel="#{it.name}"></f:selectitems> <f:selectitem itemvalue="#{data.onePerson}" itemlabel="#{data.onePerson.name}"></f:selectitem> </p:selectonemenu>

And this is what I wrote:

<p:selectonemenu id="manager" value="{data.manager}" converter="ivy.ListItem" style="width: 200px;"> <f:selectitems value="#{data.managers}" var="it" itemvalue="#{it}" itemlabel="#{it.cn}"></f:selectitems> </p:selectonemenu>

Is there something I've forgotten? This looks exactly the same to me. Do I have to do something when I submit? I've got a multiview HTML dialog.