diff -ur roundcubemail-0.5.1.old/installer/index.php roundcubemail-0.5.1/installer/index.php
--- roundcubemail-0.5.1.old/installer/index.php	2010-09-25 15:03:53.000000000 +0200
+++ roundcubemail-0.5.1/installer/index.php	2011-02-21 11:03:44.000000000 +0100
@@ -4,7 +4,7 @@
 ini_set('display_errors', 1);
 
 define('INSTALL_PATH', realpath(dirname(__FILE__) . '/../').'/');
-define('RCMAIL_CONFIG_DIR', INSTALL_PATH . 'config');
+define('RCMAIL_CONFIG_DIR', '/etc/roundcubemail');
 
 $include_path  = INSTALL_PATH . 'program/lib' . PATH_SEPARATOR;
 $include_path .= INSTALL_PATH . 'program' . PATH_SEPARATOR;
diff -ur roundcubemail-0.5.1.old/program/include/iniset.php roundcubemail-0.5.1/program/include/iniset.php
--- roundcubemail-0.5.1.old/program/include/iniset.php	2011-01-29 15:55:12.000000000 +0100
+++ roundcubemail-0.5.1/program/include/iniset.php	2011-02-21 11:02:18.000000000 +0100
@@ -40,14 +40,13 @@
 define('RCMAIL_CHARSET', 'UTF-8');
 define('JS_OBJECT_NAME', 'rcmail');
 define('RCMAIL_START', microtime(true));
+define('RCMAIL_CONFIG_DIR', '/etc/roundcubemail');
 
 if (!defined('INSTALL_PATH')) {
     define('INSTALL_PATH', dirname($_SERVER['SCRIPT_FILENAME']).'/');
 }
 
-if (!defined('RCMAIL_CONFIG_DIR')) {
-    define('RCMAIL_CONFIG_DIR', INSTALL_PATH . 'config');
-}
+
 
 // make sure path_separator is defined
 if (!defined('PATH_SEPARATOR')) {