Applied patch from #97053

search_config.module

@@ -91,13 +91,22 @@ function search_config_form_alter($form_id, &$form) {
           }
         
           // Rebuild form item -- copied from node.module
-          $form['advanced']['type'] = array(
-            '#type' => 'checkboxes',
-            '#title' => t('Only of the type(s)'),
-            '#prefix' => '<div class="criterion">',
-            '#suffix' => '</div>',
-            '#options' => $types,
-          );
+          if (count($types) == 1) {
+            $type_keys = array_keys($types);
+            $form['advanced']['type'] = array(
+              '#type' => 'hidden',
+              '#default_value' => $type_keys[0],
+            );
+          } 
+          else {
+            $form['advanced']['type'] = array(
+              '#type' => 'checkboxes',
+              '#title' => t('Only of the type(s)'),
+              '#prefix' => '<div class="criterion">',
+              '#suffix' => '</div>',
+              '#options' => $types,
+            );
+          }
         }
   
         // Taxonomy