=== modified file 'includes/install.inc'
--- includes/install.inc	2007-11-30 12:19:10 +0000
+++ includes/install.inc	2007-12-05 11:44:59 +0000
@@ -22,8 +22,10 @@ define('FILE_NOT_EXECUTABLE', 128);
  * Initialize the update system by loading all installed module's .install files.
  */
 function drupal_load_updates() {
-  foreach (module_list() as $module) {
-    module_load_install($module);
+  foreach (drupal_get_installed_schema_version(NULL, FALSE, TRUE) as $module => $schema_version) {
+    if ($schema_version > -1) {
+      module_load_install($module);
+    }
   }
 }
 
@@ -58,10 +60,15 @@ function drupal_get_schema_versions($mod
  *
  * @param $module
  *   A module name.
+ * @param $reset
+ *   Set to TRUE after modifying the system table.
+ * @param $array
+ *   Set to TRUE if you want to get information about all modules in the 
+ *   system.
  * @return
  *   The currently installed schema version.
  */
-function drupal_get_installed_schema_version($module, $reset = FALSE) {
+function drupal_get_installed_schema_version($module, $reset = FALSE, $array = FALSE) {
   static $versions = array();
 
   if ($reset) {
@@ -76,7 +83,7 @@ function drupal_get_installed_schema_ver
     }
   }
 
-  return $versions[$module];
+  return $array ? $versions : $versions[$module];
 }
 
 /**

=== modified file 'modules/comment/comment.install'
--- modules/comment/comment.install	2007-11-26 19:55:15 +0000
+++ modules/comment/comment.install	2007-12-05 11:44:59 +0000
@@ -1,6 +1,8 @@
 <?php
 // $Id: comment.install,v 1.11 2007/11/26 19:55:15 goba Exp $
 
+require_once drupal_get_path('module', 'comment') .'/comment.module';
+
 /**
  * Implementation of hook_enable().
  */

=== modified file 'modules/system/system.install'
--- modules/system/system.install	2007-11-30 18:11:29 +0000
+++ modules/system/system.install	2007-12-05 11:44:59 +0000
@@ -1040,6 +1040,10 @@ function system_schema() {
  * @{
  */
 
+function system_update_last_removed() {
+  return 179;
+}
+
 function system_update_180() {
   $ret = array();
 

=== modified file 'update.php'
--- update.php	2007-11-30 12:19:10 +0000
+++ update.php	2007-12-05 11:45:15 +0000
@@ -334,19 +334,28 @@ function update_script_selection_form() 
   // Ensure system.module's updates appear first
   $form['start']['system'] = array();
 
-  foreach (module_list() as $module) {
+  $modules = drupal_get_installed_schema_version(NULL, FALSE, TRUE);
+  foreach ($modules as $module => $schema_version) {
     $updates = drupal_get_schema_versions($module);
-    if ($updates !== FALSE) {
+    if ($updates !== FALSE && $schema_version >= 0) {
+      // module_invoke returns NULL for nonexisting hooks, so if no updates
+      // are removed, it will == 0.
+      $last_removed = module_invoke($module, 'update_last_removed');
+      if ($schema_version < $last_removed) {
+        $form['start'][$module] = array(
+          '#value' => "$module can not be updated. It's schema version is $schema_version and updates up to $last_removed have been removed. You need to install an older version of Drupal and update this module first if you want to use $module in the future.",
+        );
+        continue;
+      }
       $updates = drupal_map_assoc($updates);
       $updates[] = 'No updates available';
-      $default = drupal_get_installed_schema_version($module);
+      $default = $schema_version;
       foreach (array_keys($updates) as $update) {
-        if ($update > $default) {
+        if ($update > $schema_version) {
           $default = $update;
           break;
         }
       }
-
       $form['start'][$module] = array(
         '#type' => 'select',
         '#title' => $module .' module',