Index: member.rb
===================================================================
--- member.rb	(revision 19489)
+++ member.rb	(working copy)
@@ -64,15 +64,14 @@
     ids = (arg || []).collect(&:to_i) - [0]
     # Keep inherited roles
     ids += member_roles.select {|mr| !mr.inherited_from.nil?}.collect(&:role_id)
-
-    new_role_ids = ids - role_ids
-    # Add new roles
-    new_role_ids.each {|id| member_roles << MemberRole.new(:role_id => id, :member => self) }
     # Remove roles (Rails' #role_ids= will not trigger MemberRole#on_destroy)
     member_roles_to_destroy = member_roles.select {|mr| !ids.include?(mr.role_id)}
     if member_roles_to_destroy.any?
       member_roles_to_destroy.each(&:destroy)
     end
+    member_roles.reload
+    # Add new roles
+    super(ids)
   end
 
   def <=>(member)