=== modified file 'modules/system/system.install'
--- modules/system/system.install	2009-06-21 03:07:43 +0000
+++ modules/system/system.install	2009-06-23 04:35:06 +0000
@@ -393,31 +393,37 @@
 
   // Add input formats.
   db_query("INSERT INTO {filter_formats} (name, roles, cache) VALUES ('%s', '%s', %d)", 'Filtered HTML', ',' . DRUPAL_ANONYMOUS_RID . ',' . DRUPAL_AUTHENTICATED_RID . ',', 1);
+  $filtered_html_format = db_last_insert_id('filter_formats', 'format');
   db_query("INSERT INTO {filter_formats} (name, roles, cache) VALUES ('%s', '%s', %d)", 'Full HTML', '', 1);
+  $full_html_format = db_last_insert_id('filter_formats', 'format');
 
   // Enable filters for each input format.
 
   // Filtered HTML:
   // URL filter.
-  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", 1, 'filter', 2, 0);
+  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", $filtered_html_format, 'filter', 2, 0);
   // HTML filter.
-  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", 1, 'filter', 0, 1);
+  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", $filtered_html_format, 'filter', 0, 1);
   // Line break filter.
-  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", 1, 'filter', 1, 2);
+  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", $filtered_html_format, 'filter', 1, 2);
   // HTML corrector filter.
-  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", 1, 'filter', 3, 10);
+  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", $filtered_html_format, 'filter', 3, 10);
 
   // Full HTML:
   // URL filter.
-  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", 2, 'filter', 2, 0);
+  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", $full_html_format, 'filter', 2, 0);
   // Line break filter.
-  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", 2, 'filter', 1, 1);
+  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", $full_html_format, 'filter', 1, 1);
   // HTML corrector filter.
-  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", 2, 'filter', 3, 10);
-
-  db_query("INSERT INTO {variable} (name, value) VALUES ('%s','%s')", 'filter_html_1', 'i:1;');
-
-  db_query("INSERT INTO {variable} (name, value) VALUES ('%s', '%s')", 'node_options_forum', 'a:1:{i:0;s:6:"status";}');
+  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", $full_html_format, 'filter', 3, 10);
+
+  // Set the default input format to filtered html.
+  variable_set('filter_default_format', $filtered_html_format);
+
+  variable_set('filter_html_1', 'i:1;');
+
+  variable_set('node_options_forum', 'a:1:{i:0;s:6:"status";}');
+
 }
 
 /**