Having a problem with WP Menu integration.

[Shane74340]

I've figured out how to integrate the WordPress menu into SMF and it works great. However, when I try to use a custom menu (WP>Dashboard>Appearance>Menus) I get the following error:

Fatal error: Call to a member function get_extra_permastruct() on a non-object in C:\wamp\www\wordpress\wp-includes\taxonomy.php on line 2945
Call Stack
#   Time   Memory   Function   Location
1   0.0030   476888   {main}( )   ..\index.php:0
2   0.0779   4458760   obExit( )   ..\index.php:154
3   0.0780   4500904   template_header( )   ..\Subs.php:2793
4   0.0826   4645352   loadSubTemplate( )   ..\Subs.php:3351
5   0.0826   4645416   template_html_above( )   ..\Load.php:1863
6   0.2546   22530952   wp_nav_menu( )   ..\Load.php(2151) : eval()'d code:275
7   0.2559   22549480   wp_get_nav_menu_items( )   ..\nav-menu-template.php:168
8   0.2667   22586032   array_map ( )   ..\nav-menu.php:530
9   0.2667   22586480   wp_setup_nav_menu_item( )   ..\nav-menu.php:530
10   0.2669   22587088   get_term_link( )   ..\nav-menu.php:604

I have no idea what's going on here.

Any ideas?