-        char temp[128];
-        sprintf(temp,
-                "*** Unknown class name %s, tell Robin about it please ***",
-                buff);
-        obj = PyString_FromString(temp);
-        return obj;
+        wxString msg(wxT("wxPython class not found for "));
+        msg += className;
+        PyErr_SetString(PyExc_NameError, msg.mbc_str());
+        return NULL;