diff -r 8bf2337a6f3b -r 5f8e52d722c5 web/formwidgets.py
--- a/web/formwidgets.py	Thu Mar 10 12:03:37 2011 +0100
+++ b/web/formwidgets.py	Thu Mar 10 12:04:46 2011 +0100
@@ -770,7 +770,7 @@
             fname = entity.autocomplete_initfuncs[field.name]
         else:
             fname = self.autocomplete_initfunc
-        return entity._cw.datadir_url + fname
+        return entity._cw.data_url(fname)
 
 
 class RestrictedAutoCompletionWidget(AutoCompletionWidget):