Error Message upon activation

I just activated the Business Portfolio theme and have a white screen with just the following message:

Fatal error: Cannot redeclare bp_dtheme_ajax_querystring() in C:\WampDeveloper\Websites\\webroot\wp-content\themes\business-portfolio\_inc\ajax.php on line 20

This is just a normal WP install, not multisite. Other themes are working ok.

I've noticed that all the wpmudev themes I've tried are giving the same message, is this an Ajax problem? If so, does anybody know what I would need to add to my server to have Ajax working?