Index: bp-themes/bp-default/functions.php
===================================================================
--- bp-themes/bp-default/functions.php	(revision 2184)
+++ bp-themes/bp-default/functions.php	(working copy)
@@ -50,12 +50,20 @@
 		return $fullname[0];
 }
 
+function bp_dtheme_warn_deactivated() {
+	echo "<div class='updated fade'><h3>" . __( 'BuddyPress is not active, please change themes', 'buddypress') .  "</h3></div>";
+}
+
 function bp_dtheme_remove_redundant() {
 	global $bp;
 
 	/* Remove the redundant "My Posts and My Comments" options since we can use filters on the activity stream. */
-	bp_core_remove_subnav_item( $bp->blogs->slug, 'recent-posts' );
-	bp_core_remove_subnav_item( $bp->blogs->slug, 'recent-comments' );
+	if( isset( $bp ) ) {
+		bp_core_remove_subnav_item( $bp->blogs->slug, 'recent-posts' );
+		bp_core_remove_subnav_item( $bp->blogs->slug, 'recent-comments' );
+	} elseif( is_admin( ) ) {
+		add_action( 'admin_notices', 'bp_dtheme_warn_deactivated' );
+	}
 }
 add_action( 'init', 'bp_dtheme_remove_redundant' );