Index: bp-core/bp-core-template.php
===================================================================
--- bp-core/bp-core-template.php
+++ bp-core/bp-core-template.php
@@ -494,9 +494,9 @@ function bp_action_variables() {
  */
 function bp_action_variable( $position = 0 ) {
 	$action_variables = bp_action_variables();
-	
+
 	$action_variable = isset( $action_variables[$position] ) ? $action_variables[$position] : false;
-	
+
 	return apply_filters( 'bp_action_variable', $action_variable, $position );
 }
 
@@ -748,13 +748,13 @@ function bp_is_current_action( $action = '' ) {
  * @param int $position The array key you're testing against. If you don't provide a $position,
  *   the function will return true if the $action_variable is found *anywhere* in the action
  *   variables array.
- * @return bool 
+ * @return bool
  */
 function bp_is_action_variable( $action_variable = '', $position = false ) {
 	$is_action_variable = false;
-	
+
 	if ( false !== $position ) {
-		// When a $position is specified, check that slot in the action_variables array		
+		// When a $position is specified, check that slot in the action_variables array
 		if ( $action_variable ) {
 			$is_action_variable = $action_variable == bp_action_variable( $position );
 		} else {
@@ -766,7 +766,7 @@ function bp_is_action_variable( $action_variable = '', $position = false ) {
 		// When no $position is specified, check the entire array
 		$is_action_variable = in_array( $action_variable, (array)bp_action_variables() );
 	}
-	
+
 	return apply_filters( 'bp_is_action_variable', $is_action_variable, $action_variable, $position );
 }
 
@@ -825,7 +825,7 @@ function bp_is_directory() {
  */
 function bp_is_root_component( $component_name ) {
 	global $bp;
-	
+
 	if ( !isset( $bp->active_components ) )
 		return false;
 
@@ -912,7 +912,7 @@ function bp_is_profile_component() {
 }
 
 function bp_is_activity_component() {
-	if ( bp_is_current_component( 'activity' ) )
+	if ( bp_is_current_component( 'activity' ) || bp_is_current_component( bp_get_activity_slug() ) )
 		return true;
 
 	return false;
@@ -966,7 +966,7 @@ function bp_is_settings_component() {
 function bp_is_single_activity() {
 	global $bp;
 
-	if ( bp_is_current_component( 'activity' ) && is_numeric( $bp->current_action ) )
+	if ( bp_is_activity_component() && is_numeric( $bp->current_action ) )
 		return true;
 
 	return false;
@@ -997,7 +997,7 @@ function bp_is_user() {
 function bp_is_user_activity() {
 	global $bp;
 
-	if ( bp_is_current_component( 'activity' ) )
+	if ( bp_is_activity_component() )
 		return true;
 
 	return false;
@@ -1026,7 +1026,7 @@ function bp_is_user_profile_edit() {
 
 	if ( bp_is_current_component( 'xprofile' ) && bp_is_current_action( 'edit' ) )
 		return true;
-		
+
 	return false;
 }
 
Index: bp-members/bp-members-loader.php
===================================================================
--- bp-members/bp-members-loader.php
+++ bp-members/bp-members-loader.php
@@ -109,7 +109,7 @@ class BP_Members_Component extends BP_Component {
 		/** Default Profile Component *****************************************/
 		if ( !defined( 'BP_DEFAULT_COMPONENT' ) ) {
 			if ( bp_is_active( 'activity' ) && isset( $bp->pages->activity ) )
-				$bp->default_component = $bp->activity->id;
+				$bp->default_component = bp_get_activity_slug();
 			else
 				$bp->default_component = ( 'xprofile' == $bp->profile->id ) ? 'profile' : $bp->profile->id;