Index: date_api.admin.inc
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/date/Attic/date_api.admin.inc,v
retrieving revision 1.1.2.1
diff -u -p -r1.1.2.1 date_api.admin.inc
--- date_api.admin.inc	25 Jan 2009 13:03:13 -0000	1.1.2.1
+++ date_api.admin.inc	20 Feb 2009 00:37:18 -0000
@@ -131,6 +131,15 @@ function date_api_date_format_form_eleme
   }
 }
 
+function date_api_date_time_settings_validate($form, &$form_state) {
+  $all_formats = date_get_formats();
+  foreach ($all_formats as $type => $formats) {
+    if (in_array($form_state['values']['add_date_format'], array_keys($formats))) {
+      form_set_error('add_date_format', t('This format already exists.  Please enter a unique format string.'));
+    }
+  }
+}
+
 function date_api_date_time_settings_submit($form, &$form_state) {
   if (!empty($form_state['values']['add_date_format'])) {
     $format = array();
Index: date/date.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/date/date/date.module,v
retrieving revision 1.61.2.4.2.47
diff -u -p -r1.61.2.4.2.47 date.module
--- date/date.module	13 Feb 2009 23:07:50 -0000	1.61.2.4.2.47
+++ date/date.module	20 Feb 2009 00:37:20 -0000
@@ -279,13 +279,16 @@ function date_theme() {
       ),  
   );
 
-  $format_types = date_get_format_types('', TRUE);
-  if (!empty($format_types)) {
-    foreach ($format_types as $type => $type_info) {
-      $themes['date_formatter_' . $type] = $base + array(
-        'arguments' => array('element' => NULL), 
-        'function' => 'theme_date_display_combination',
-      );
+  // Table isn't available first time date_theme() is called in update.php.
+  if (db_table_exists('date_format_types')) {
+    $format_types = date_get_format_types('', TRUE);
+    if (!empty($format_types)) {
+      foreach ($format_types as $type => $type_info) {
+        $themes['date_formatter_' . $type] = $base + array(
+          'arguments' => array('element' => NULL), 
+          'function' => 'theme_date_display_combination',
+        );
+      }
     }
   }