BuddyPress.org

In bp-blogs.php, change 379 from
if ( (int)get_blog_option( $blog_id, 'blog_public' ) || !bp_core_is_multisite() ) {
to
if ( (get_blog_option( $blog_id, 'blog_public' ) > 0 || !bp_core_is_multisite() ) {

Also, change 427 from
if ( (int)get_blog_option( $recorded_comment->blog_id, 'blog_public' ) || !bp_core_is_multisite() ) {
to
if ( (get_blog_option( $recorded_comment->blog_id, 'blog_public' ) > 0 || !bp_core_is_multisite() ) {

I haven’t tested this but it should work.