Add mention of duplicate connection messages from psql, per Andrew.

doc/src/sgml/config.sgml

 <!--
-$PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.20 2005/09/23 02:06:58 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.21 2005/09/24 23:06:24 momjian Exp $
 -->
 <chapter Id="runtime-config">
   <title>Run-time Configuration</title>
@@ -2544,7 +2544,10 @@ SELECT * FROM parent WHERE key = 2400;
        <para>
         This outputs a line to the server log detailing each successful
         connection. This is off by default, although it is probably very
-        useful. This option can only be set at server start or in the
+        useful.  Some client programs, like <application>psql</>, will
+        attempt to connect twice while determining if a password is required
+        so duplicate <literal>connection received</> messasges are not a sign
+        of  problem.  This option can only be set at server start or in the
         <filename>postgresql.conf</filename> configuration file.
        </para>
       </listitem>