Weird Error

I've tinkered with the Buisness theme before and passed it by but I'm going back to look at it again and I get this error both in the preview and when I activate it.

Cannot redeclare bp_dtheme_ajax_querystring() (previously declared in /home/delcom10/public_html/wp-content/themes/bp-business/_inc/ajax.php:17) in /home/delcom10/public_html/wp-content/plugins/buddypress/bp-themes/bp-default/_inc/ajax.php on line 81