Index: kbuildsycoca.cpp
===================================================================
--- kbuildsycoca.cpp	(revision 792080)
+++ kbuildsycoca.cpp	(working copy)
@@ -743,9 +743,15 @@
      quint32 current_update_sig = KGlobal::dirs()->calcResourceHash("services", "update_ksycoca",
                                                                     KStandardDirs::Recursive );
      quint32 ksycoca_update_sig = KSycoca::self()->updateSignature();
-
+#ifdef Q_WS_WIN
+     QString current_prefixes = KGlobal::dirs()->kfsstnd_prefixes();
+     QString ksycoca_prefixes = KSycoca::self()->kfsstnd_prefixes();
+#endif
      if ((current_update_sig != ksycoca_update_sig) ||
          (current_language != ksycoca_language) ||
+#ifdef Q_WS_WIN
+         (current_prefixes != ksycoca_prefixes) ||
+#endif
          (KSycoca::self()->timeStamp() == 0))
      {
         incremental = false;