http://markmail.org/message/q4jwuljoxo36u6j2
http://freecode.com/projects/courier-authlib/releases/348728
http://courier.svn.sourceforge.net/viewvc/courier/trunk/courier-authlib/authpgsqllib.c?view=patch&r1=239&r2=238&pathrev=239

--- authpgsqllib.c	2008-12-18 13:08:25.000000000 +0100
+++ authpgsqllib.c.oden	2012-10-12 10:29:12.035061707 +0200
@@ -220,6 +220,7 @@ const 	char *server_opt=0;
        			userid ? userid : "<null>",
        			database);
         	err("%s", PQerrorMessage(pgconn));
+		PQfinish(pgconn);
 		pgconn=0;
 		return -1;
     	}