[z3-five] handler not getting called

[yary]

I'm trying to add a handler, but it doesn't get called. ZCML:

    <five:traversable class=".portal.QSite" />
    <five:traversable class="OFS.Folder.Folder" />
    <five:implements class=".portal.QSite"
          interface=".portal.IQSite"
          />
      <subscriber
      for=".portal.IQSite zope.app.container.interfaces.IObjectEvent"
      handler=".portal.addedQSite"
      />

currently addedQSite prints a debug message and then throws an
exception- trying to make it hard to miss... but I can create a QSite
and not see the debug message or exception. My first attempt I used
IObjectAddedEvent, and switched to IObjectEvent to try and catch any
event, still nothing calls my addedQSite on add or delete. Any ideas
on how to fix?