BuddyPress.org

Let’s recap this modemlooper. You have running:

– bp 1.0 RC-1

– wpmu 2.7 release version not beta

– You’ve tried using just the distributed home theme and member theme without plugins or other js using enhancements.

– You say the permissions are 755 on that directory and file (bp-core-ajax-handler.php)

What version PHP is on your server. You need PHP 5.x.