Tunnel Problem!!

Hallo,
we are a small ISP working in Germany and our client network work completly with Mikrotiks RouterBoard and Ubiquiti Antenne,
this is our diagram .http://www.pic-upload.de/view-30125714/Diagram.png.html
we are using Mikrotik 1 as PPPOE client for first internet line.
Mikrotik 2 used as load balacing and failover between first line and second internet line
mikrotik 3 used as Eoip tunnel to virtual machine server for client registration over PPPOE Server
mikrotik 4 as mikrotik 2 configurated…, mikrotik 5 as mikrotik 3 configurated

problem is that the Eoip tunnel dont work on mikrotik 3 or 5,
work on mikrotik 1 or mikrotik 2 and 4 without load balancing failover.
any help how to get this diagram as its made to work and the tunnel in mikrotik 3 and 5.
ps: we can ping the virtual machine mikrotik ip addresse from mikrotik 3 and 5.
thank you and sorry for bad english:)

Schreib mich mal per PN an dann können wir das in deutsch besprechen. Ist vielleicht einfacher

Guten Tag . vielen dank für Ihr antwort ich bin neu hier ubd weiss es nicht wie kann ich Sie per PN schreiben . gruss und schöne Ostern