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\indief.com\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.

EDIT:
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?