Index: jquery_ui.module
===================================================================
--- jquery_ui.module  (revision 459)
+++ jquery_ui.module  (working copy)
@@ -20,7 +20,7 @@
  *   on the page, or a string with a single file name.
  */
 function jquery_ui_add($files = array()) {
-  static $loaded_files, $ui_core, $effects_core;
+  static $loaded_files, $dependencies = array();
 
   $jquery_ui_path = jquery_ui_get_path();
   if ($jquery_ui_path === FALSE) {
@@ -28,6 +28,14 @@
   }
   $jquery_ui_path .= '/ui';
   $compression = variable_get('jquery_update_compression_type', 'mini');
+  $jquery_ui_version = version_compare(jquery_ui_get_version(), '1.8', '>=') ? 'jquery.' : '';
+
+  if (empty($dependencies)) {
+    $cache_dependencies = cache_get('jquery_ui_dependencies');
+    if ($cache_dependencies->data) {
+      $dependencies = $cache_dependencies->data;
+    }
+  }
 
   // Convert file to an array if it's not one already, to compensate for
   // lazy developers. ;)
@@ -35,20 +43,9 @@
     $files = array($files);
   }
 
-  // If core hasn't been added yet, add it.
-  if (!isset($ui_core)) {
-    $ui_core = TRUE;
-    jquery_ui_add(array('ui.core'));
-  }
-
   // Loop through list of files to include and add them to the page.
   foreach ($files as $file) {
-    // Any effects files require the effects core file.
-    if (!isset($effects_core) && strpos($file, 'effects.') === 0) {
-      $effects_core = TRUE;
-      jquery_ui_add(array('effects.core'));
-    }
-
+    $file = $jquery_ui_version . $file;
     // Load other files.
     if (!isset($loaded_files[$file])) {
       switch ($compression) {
@@ -66,10 +63,27 @@
           break;
       }
       $js_path = $jquery_ui_path . '/' . $file_path;
+      
+      if (!isset($dependencies[$file])) {
+        $file_contents = file_get_contents($js_path);
+        preg_match('/^\/\*.*Depends:(.*?)\*\//ismu', $file_contents, $matches);
+        preg_match_all('/\s*\*\s*(jquery\.)?(.+)\n/miu', $matches[1], $depends);
+        
+        $dependencies[$file] = $depends[2];
+        foreach ($dependencies[$file] as &$depend) {
+          $depend = basename(trim($depend), '.js');
+        }
+      }
+      
+      if (!empty($dependencies[$file])) {
+        jquery_ui_add($dependencies[$file]);
+      }
+      
       drupal_add_js($js_path);
       $loaded_files[$file] = $js_path;
     }
   }
+  cache_set('jquery_ui_dependencies', $dependencies);
 }
 
 /**