Since you are talking about Eastern orthodoc churches, I heared from a russian orthodox, that the russian orthodox church slpit unoficialy, a part the accepted communism, and the part that refused it , now another hidden issue pops out, is that most of the orthodox that refused communism, were forced to become orthodox, so this issue might affect the russian orthodox church .
Now about the Eastern orthodox and Oriental orthodox, OH boy, i thought the catholic/protestant relation is bad, until i saw the eastern orthodox and oriental orthodox issues. It is an issue of monophisim that oriental churches beleive in ( Syriac,Coptic,Armenain,Ethiopean...etc ) .
Also note what is written :
Having thus summarily disposed of the insuperable dogmatic barrier between the Truth of Orthodoxy and the falsehood of Non-Chalcedonianism, the symposium quickly turned its attention to the "practical steps...which could be implemented at the global and local levels to ultimately achieve [sic] unity," and "this includes among other things, a statement of reconciliation, academic cooperation, and common catechesis of young people" (ibid.). Deciphering this "ecumenically correct" jargon and restating it in plain Orthodox language, this symposium embraced the renunciation of Patristic Tradition, the scholarly prostitution of sacred theology, and the sacrifice of the next generation of Orthodox to appease the Moloch of Monophysitism. And for this, we have to thank "the great contribution of modern scholarship and the current worldwide ecumenical movement" (ibid.)! The words of the Savior ring with prophetic force: "Ye shall know them by their fruits" (St. Matthew 7:16).
In contrast to our ecumenist counterparts, who—to the detriment of their fellow man—reinforce the Monophysites in their error, we traditionalists, out of love both for the Truth and for those who have deviated from it, challenge the Monophysites to accept the standard of True Orthodox Christianity. Let the Non-Chalcedonian heretics become truly Oriental Orthodox: Let their spiritual orientation turn eastward, facing the Chalcedonian sunrise that dawns universally from the noetic Anatolia of Eastern Orthodoxy, where the Theanthropic One, "Whose Name is Orient" (Zechariah 6:12 [LXX]), the God-Man Christ Jesus, rises in Truth. Only then, when they have renounced their heterodox beliefs, can we genuinely address these theologically disoriented Easterners as Orthodox brethren.
From Orthodox Tradition, Vol. XIII, No. 1, 1996, pp. 20-22.
You find this at : http://www.orthodoxinfo.com/ecumenism/east_orth.aspx
along other stuff. So I dont know what is going on with them, but it is bad, Please pray for their unity with each other and Us.