--- a/selectors.py	Fri Oct 21 09:23:43 2011 +0200
+++ b/selectors.py	Fri Oct 21 10:59:57 2011 +0200
@@ -303,7 +303,7 @@
         else:
             etype = rset.description[row][col]
             # may have None in rset.description on outer join
-            if etype is None:
+            if etype is None or rset.rows[row][col] is None:
                 return 0
             etypes = (etype,)
         score = 0