Index: teaser_block.module
===================================================================
--- teaser_block.module	(Revision 157)
+++ teaser_block.module	(Arbeitskopie)
@@ -108,6 +108,40 @@ function theme_teaser_block_read_more_li
   return $content;
 }
 
+/**
+ * Implementation of hook_form_alter().
+ *
+ * Allows to enable/disable content-types for teaser blocks.
+ */
+function teaser_block_form_alter($form_id, &$form) {
+  if ($form_id == 'node_type_form' && isset($form['identity']['type'])) {
+    $types = variable_get('teaser_block_types', array());
+    $form['workflow']['teaser_block'] = array(
+      '#type' => 'radios',
+      '#title' => t('Teaser blocks'),
+      '#default_value' => (int)isset($types[$form['#node_type']->type]),
+      '#options' => array(t('Disabled'), t('Enabled')),
+      '#description' => t('Enables teaser blocks for this content-type.'),
+    );
+    $form['#submit'] = array('teaser_block_node_type_submit' => array()) + (array)$form['#submit'];
+  }
+}
+
+/**
+ * Submit handler for node type form.
+ */
+function teaser_block_node_type_submit($form_id, &$form_values) {
+  $types = variable_get('teaser_block_types', array());
+  if ($form_values['teaser_block']) {
+    $types = array_merge($types, array($form_values['type'] => $form_values['teaser_block']));
+  }
+  else {
+    unset($types[$form_values['type']]);
+  }
+  variable_set('teaser_block_types', $types);
+  unset($form_values['teaser_block']);
+}
+
 function teaser_block_form($delta = 0) {
   $teaser_block = db_fetch_array(db_query('SELECT bid, nid, title, body, format FROM {teaser_block} WHERE bid = %d', $delta));
 
@@ -124,7 +158,9 @@ function teaser_block_form($delta = 0) {
   );
 
   $options = array('' => t('- Please select -'));
-  $result = db_query(db_rewrite_sql('SELECT n.nid, n.title FROM node n ORDER BY n.title'));
+  $types = variable_get('teaser_block_types', array());
+  $types = (!empty($types) ? "WHERE n.type IN ('". implode("','", array_keys($types)) ."')" : '');
+  $result = db_query(db_rewrite_sql('SELECT n.nid, n.title FROM node n '. $types .' ORDER BY n.title'));
   while ($node = db_fetch_object($result)) {
     $options[$node->nid] = $node->title;
   }
Index: README.txt
===================================================================
--- README.txt	(Revision 156)
+++ README.txt	(Arbeitskopie)
@@ -25,7 +25,11 @@ None.
 
 -- CONFIGURATION --
 
-* Configure user permissions in administer >> Access control >> Teaser block.
+* Configure user permissions in administer >> User management >> Access control
+  >> Teaser block.
+
+* Enable the linkable content-types in administer >> Content management >>
+  Content types.  All content-types are disabled by default.
 
 
 -- USAGE --