[Plugin: Admin Customization] Wrong datatype for second argument

Everything appears fine until I try and go to the Dashboard in the Admin panel then I get about 16 copies of the same error code in the header area of the admin panel. This is the error:

Warning: in_array() [function.in-array]: Wrong datatype for second argument in /home/wendymer/public_html/erskinanavitarte.com/wp-content/plugins/admin-customization/core.php on line 160

Your help would be much appreciated.