Don't try to use unsupported DB versions.
diff --git a/setup.py b/setup.py
index c94df0b..f471c03 100644
--- a/setup.py
+++ b/setup.py
@@ -439,21 +439,15 @@
         # when sorted in reverse order, keys for this dict must appear in the
         # order you wish to search - e.g., search for db4 before db3
         db_try_this = {
-            'db4': {'libs': ('db-4.3', 'db-4.2', 'db-4.1', 'db-4.0'),
-                    'libdirs': ('/usr/local/BerkeleyDB.4.3/lib',
-                                '/usr/local/BerkeleyDB.4.2/lib',
-                                '/usr/local/BerkeleyDB.4.1/lib',
-                                '/usr/local/BerkeleyDB.4.0/lib',
+            'db4': {'libs': ('db-4.0',),
+                    'libdirs': ('/usr/local/BerkeleyDB.4.0/lib',
                                 '/usr/local/lib',
                                 '/usr/lib',
                                 '/opt/sfw',
                                 '/sw/lib',
                                 '/lib',
                                 ),
-                    'incdirs': ('/usr/local/BerkeleyDB.4.3/include',
-                                '/usr/local/BerkeleyDB.4.2/include',
-                                '/usr/local/BerkeleyDB.4.1/include',
-                                '/usr/local/BerkeleyDB.4.0/include',
+                    'incdirs': ('/usr/local/BerkeleyDB.4.0/include',
                                 '/usr/local/include/db4',
                                 '/opt/sfw/include/db4',
                                 '/sw/include/db4',