Come on, you have at least two denominations out of the same church. Now that we have established that schisms are not the sole province of "protestants" and it's just a matter of numbers, at least the schisms in the "protestants" are doctrinal, with the separation dealing with fidelity to the gospel, not territorial and political. Here is a popular history of the split between OCA and ROCOR.http://orthodoxwiki.org/ROCOR_and_OCA.
"Some orthodox churches have attended the WCC and NCC"
You are being too generous. They are full members. Our churches vote with their feet when the disagreement is a fundamental spiritual disagreement. We come apart and go our separate ways rather than being seen to agree with an unbiblical position.
actually they're not full members they're associate members; they're there to witness to Christian truth.
the orthodoxwiki article is outdated.
see this:
http://www.oca.org/News.asp?ID=1167&SID=19#%22PHOTOindex.asp?SID=11%22