Port flapping RB5009 + vodafone modem

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We also having this port flapping issue with RB5009.
All connected ports are going down and up (The 2.5 and 1g ports too). Sometimes once per day, sometimes twice in 10 minutes. This is extremely uncomfortable, because this drops the pppoe connection and we have to wait 10 minutes until the pppoe session timeouts at the ISP side and we got authenticated again.

Do you by any chance have DHCP Leases window open in Winbox when all connected ports are flapping? See http://forum.mikrotik.com/t/rb5009-all-connected-ports-flap-a-few-times-a-day/155042/2
The single port flapping is a different issue after all so you should post in the linked thread rather.