Klocwork made another run and found a bunch more problems.
This is the first batch of fixes that should be easy to verify based on context.

This fixes problem numbers: 220 (ast), 323-324 (symtable),
321-322 (structseq), 215 (array), 210 (hotshot), 182 (codecs), 209 (etree).
diff --git a/Modules/_elementtree.c b/Modules/_elementtree.c
index b468e71..c9e524f 100644
--- a/Modules/_elementtree.c
+++ b/Modules/_elementtree.c
@@ -809,7 +809,7 @@
             PyObject* text = element_get_text(item);
             if (text == Py_None)
                 return PyString_FromString("");
-            Py_INCREF(text);
+            Py_XINCREF(text);
             return text;
         }
     }