Disabling items with PrimeFaces SelectOneMenu with custom content / p:column - jsf

Question

it seems as if it is not possible to disable items in a SelectOneMenu from PrimeFaces (3.3) when using the custom content (as shown at http://www.primefaces.org/showcase-labs/ui/selectOneMenu.jsf).
The testcase is simple, just take the following:
<h:form>
<p:selectOneMenu value="#{testBean.selected}">
<f:selectItems value="#{testBean.options}" var="t"
itemLabel="#{t.label}" itemValue="#{t}"
itemDisabled="#{t.value % 2 == 0 ? 'true' : 'false'}" />
</p:selectOneMenu>
<p:selectOneMenu value="#{testBean.selected}" var="x">
<f:selectItems value="#{testBean.options}" var="t"
itemLabel="#{t.label}" itemValue="#{t}"
itemDisabled="#{t.value % 2 == 0 ? 'true' : 'false'}" />
<p:column>
#{x.label} -- #{x.label}
</p:column>
</p:selectOneMenu>
</h:form>
and the following Java files:
Bean:
#Named
public class TestBean {
private TestObject selected;
// getter/setter
public List<TestObject> getOptions() {
return Arrays.asList(new TestObject("1"), new TestObject("2")); }
}
Object:
public class TestObject {
private Integer value;
// getter/setter
public TestObject() {}
public TestObject(String s) {
this.setLabel(s);
}
public String getLabel() {return "label: " + value;}
public void setLabel(String l) {this.value = new Integer(l);}
}
The first dropdown works fine, the second one doesn't. Any idea on how to solve that?