diff --git a/browser/form.py b/browser/form.py
index 3a68304..10ad5f1 100644
--- a/browser/form.py
+++ b/browser/form.py
@@ -101,6 +101,10 @@ class ObjectForm(NodeView):
     def defaultPredicate(self):
         return self.loopsRoot.getConceptManager().getDefaultPredicate()
 
+    @Lazy
+    def defaultPredicateUid(self):
+        return util.getUidForObject(self.defaultPredicate)
+
     @Lazy
     def typeManager(self):
         return ITypeManager(self.context)
@@ -115,7 +119,7 @@ class ObjectForm(NodeView):
     def conceptsForType(self, token):
         noSelection = dict(token='none', title=u'not selected')
         result = sorted(ConceptQuery(self).query(type=token), key=lambda x: x.title)
-        predicateUid = util.getUidForObject(self.defaultPredicate)
+        predicateUid = self.defaultPredicateUid
         return ([noSelection] +
                 [dict(title=o.title,
                       token='%s:%s' % (util.getUidForObject(o), predicateUid))
diff --git a/browser/form_macros.pt b/browser/form_macros.pt
index e1145be..b05db60 100644
--- a/browser/form_macros.pt
+++ b/browser/form_macros.pt
@@ -152,7 +152,7 @@
     <td>
       <input type="hidden"
              id="concept.search.predicate"
-             tal:attributes="value view/defaultPredicate" />
+             tal:attributes="value view/defaultPredicateUid" />
       <input dojoType="comboBox" mode="remote" autoComplete="False"
              name="concept.search.text" id="concept.search.text"
              tal:attributes="dataUrl
diff --git a/configure.zcml b/configure.zcml
index 83e1b68..3736151 100644
--- a/configure.zcml
+++ b/configure.zcml
@@ -352,6 +352,8 @@
   <adapter factory="loops.target.ConceptProxy"
            permission="zope.ManageContent" />
 
+  <!-- text conversions, e.g. for full-text indexing -->
+
   <adapter for="loops.interfaces.IFile"
            provides="cybertools.text.interfaces.ITextTransform"
            name="application/pdf"
@@ -362,6 +364,16 @@
            name="application/msword"
            factory="cybertools.text.doc.DocTransform" />
 
+  <adapter for="loops.interfaces.IFile"
+           provides="cybertools.text.interfaces.ITextTransform"
+           name="application/vnd.ms-powerpoint"
+           factory="cybertools.text.ppt.PptTransform" />
+
+  <adapter for="loops.interfaces.IFile"
+           provides="cybertools.text.interfaces.ITextTransform"
+           name="application/vnd.ms-excel"
+           factory="cybertools.text.xls.XlsTransform" />
+
   <!-- utilities -->
 
   <utility