diff --git a/translate/storage/dtd.py b/translate/storage/dtd.py
index 3d303938a6..b1a96cfe6d 100644
--- a/translate/storage/dtd.py
+++ b/translate/storage/dtd.py
@@ -58,7 +58,7 @@
 
 def quotefordtd(source):
     if '%' in source:
-        source = source.replace("%", "")
+        source = source.replace("%", "%")
     if '"' in source:
         if "'" in source:
             return "'" + source.replace("'", ''') + "'"
@@ -77,7 +77,7 @@ def unquotefromdtd(source):
     extracted, quotefinished = quote.extractwithoutquotes(source, quotechar, quotechar, allowreentry=False)
     if quotechar == "'" and "'" in extracted:
         extracted = extracted.replace("'", "'")
-    extracted = extracted.replace("", "%")
+    extracted = extracted.replace("%", "%")
     # the quote characters should be the first and last characters in the string
     # of course there could also be quote characters within the string; not handled here
     return extracted
@@ -471,6 +471,7 @@ def _valid_store(self):
             try:
                 # #expand is a Mozilla hack and are removed as they are not valid in DTDs
                 dtd = etree.DTD(StringIO.StringIO(re.sub("#expand", "", self.getoutput())))
-            except etree.DTDParseError:
+            except etree.DTDParseError as e:
+                warnings.warn("DTD parse error: %s" % e.error_log)
                 return False
         return True
diff --git a/translate/storage/test_dtd.py b/translate/storage/test_dtd.py
index 7f878519e8..e84e27852e 100644
--- a/translate/storage/test_dtd.py
+++ b/translate/storage/test_dtd.py
@@ -31,7 +31,7 @@ def tester(raw_original, dtd_ready_result):
         assert dtd.quotefordtd(raw_original) == dtd_ready_result
         #print dtd.unquotefromdtd(dtd_ready_result)
         assert dtd.unquotefromdtd(dtd_ready_result) == raw_original
-    tester("Unintentional variable %S", '"Unintentional variable S"')
+    tester("Unintentional variable %S", '"Unintentional variable %S"')
 
 def test_removeinvalidamp(recwarn):
     """tests the the removeinvalidamps function"""