[Zope] Selection Property for ZClasses

[RC Compaan]

I created a ZClass with a property "selection" and specified "mylist" as
value.  In the root of my site i have a dtml method called "mylist" to
generate a list.  When I add my new ZClass and try to modify property values
i get an error: " InError, String not allowed as input for in".

the dtml-method mylist:
  <dtml-with Folder>
    <dtml-in "objectItems('MyZClassMetaType')">
      <dtml-var sequence-item>
    </dtml-in>
  </dtml-with>

Can somebody help?

Roché Compaan