Dear Mikrotik engineers,
Thank you for the relentless development of new and improved features.
Would you consider fixing this issue: http://forum.mikrotik.com/t/l2tp-client-issue-connecting/106879/1
Imagine relying on l2tp for a backup (failover) connection, only to realise that it is not working when you need it. Well, it just happened to me. 
Regards