Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.809
diff -u -r1.809 common.inc
--- includes/common.inc	15 Oct 2008 16:05:51 -0000	1.809
+++ includes/common.inc	21 Oct 2008 14:45:18 -0000
@@ -678,7 +678,8 @@
   }
 
   // Force display of error messages in update.php.
-  if (variable_get('error_level', 1) == 1 || (defined('MAINTENANCE_MODE') && MAINTENANCE_MODE == 'update')) {
+  $error_level = variable_get('error_level', 2);
+  if ($error_level >= 2 || ($error_level == 1 && ($errno & (E_ALL ^ E_NOTICE))) || strstr($_SERVER['SCRIPT_NAME'], 'update.php') ) {
     drupal_set_message(t('@type: %message in %function (line %line of %file).', array('@type' => $type, '%message' => $message, '%function' => $caller['function'], '%line' => $caller['line'], '%file' => $caller['file'])), 'error');
   }
 
Index: modules/system/system.admin.inc
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.admin.inc,v
retrieving revision 1.102
diff -u -r1.102 system.admin.inc
--- modules/system/system.admin.inc	16 Oct 2008 20:23:08 -0000	1.102
+++ modules/system/system.admin.inc	21 Oct 2008 14:45:18 -0000
@@ -1294,8 +1294,14 @@
   );
 
   $form['error_level'] = array(
-    '#type' => 'select', '#title' => t('Error reporting'), '#default_value' => variable_get('error_level', 1),
-    '#options' => array(t('Write errors to the log'), t('Write errors to the log and to the screen')),
+    '#type' => 'radios',
+    '#title' => t('Error reporting'),
+    '#default_value' => variable_get('error_level', 2),
+    '#options' => array(
+      0 => t('Site in production: Write errors and PHP notices to the log.'),
+      1 => t('Site in development: Write errors to the log and to the screen. Write PHP notices only to the log.'),
+      2 => t('For developers: Write errors and PHP notices to both the log and the screen.'),
+    ),
     '#description' => t('Specify where Drupal, PHP and SQL errors are logged. While it is recommended that a site running in a production environment write errors to the log only, in a development or testing environment it may be helpful to write errors both to the log and to the screen.')
   );