Plugin: Add Descendants As Submenu Items / Very Slow Loading Menu

Hi,

I have installed the plugin ‘Add Descendants As Submenu Items’. Everything works fine for pages but my problem is a very slow loading of the menu. The menu itself contains about 100 pages and I have to wait for nearly 20 seconds (!). Same happens when you click the pages, not so long but still about 5 seconds to wait for each page to display.

The same menu when configured manually in the appearence > menu section loads under a second and pages show up immediately. The site itself is hosted on a dedicated server with sufficient resources, no shared hosting.

Anyone has made the same experience with slow loading larger menus related to the use of this plugin? Any thoughts how to eliminate slow loading in this issue?

http://wordpress.org/plugins/add-descendants-as-submenu-items/