Cannot delete activity BuddyPress Activity, SWA feed broken.

Everytime I try to delete anything from my activity stream I get redirected to a 404 page, plus my site-wide-activity RSS feed is broken as well. Anyone else experienced this and/or resolved it?

WPMU 2.8.6 + BP 1.1.3, subdirectory install.

I've see that some other people have experienced this over at the BP forums, but there doesn't appear to be a solution, so I thought I'd try my luck here.