Index: bp-groups/bp-groups-functions.php
===================================================================
--- bp-groups/bp-groups-functions.php	(revision 9404)
+++ bp-groups/bp-groups-functions.php	(working copy)
@@ -159,8 +159,6 @@
 		$member->date_modified = bp_core_current_time();
 		$member->save();
 
-		groups_update_groupmeta( $group->id, 'last_activity', bp_core_current_time() );
-
 		do_action( 'groups_create_group', $group->id, $member, $group );
 
 	} else {