diff --git a/branches/ucs-4.1/ucs-4.1-0/management/univention-management-console/dev/dh_umc.py b/branches/ucs-4.1/ucs-4.1-0/management/univention-management-console/dev/dh_umc.py
index bf182aa..259eb6d 100644
--- a/branches/ucs-4.1/ucs-4.1-0/management/univention-management-console/dev/dh_umc.py
+++ b/branches/ucs-4.1/ucs-4.1-0/management/univention-management-console/dev/dh_umc.py
@@ -221,15 +221,22 @@ def read_modules(package, core=False):
 def _appendPoEntry(poFile, xmlEntry):
        """Helper function to access text property of XML elements and to find the
        corresponding po-entry."""
-       if xmlEntry is not None and xmlEntry.text is not None:  # important to use "xmlEntry is non None"!
-               poFile.append(polib.POEntry(msgid=xmlEntry.text, msgstr=''))
+       if xmlEntry is None:
+               return
+       text = xmlEntry.text
+       if text is None:
+               return
+       try:
+               poFile.append(polib.POEntry(msgid=text, msgstr=''))
+       except ValueError:
+               print "I: duplicate entry: %s" % (text,)
 
 
 def module_xml2po(module, po_file, language):
        """Create a PO file the XML definition of an UMC module"""
        message_po = '%s/messages.po' % (os.path.dirname(po_file) or '.')
 
-       po = polib.POFile()
+       po = polib.POFile(check_for_duplicates=True)
        po.header = PO_HEADER
        po.metadata = copy.copy(PO_METADATA)
        po.metadata['Project-Id-Version'] = module.package