Dear Jennifer,
I think you should speak only with me because I'm known (if djs is to be believed

) to be one of the most gracious posters here!
(O.K., I fall from grace sometimes . . .)
You raise a good point, where does papal infallibility come from?
Perhaps the word itself is daunting and non-Eastern (like the words "Transubstantiation" and "Transmutation" etc.).
But it does express the fundamental truth, that the Fathers and the Councils have always taught, that the Church, as the Body of Christ, is led by the Holy Spirit and is guarded by God from error.
That is a fundamental truth that ALL Christians accept about THE Church (and also about THEIR church or community that they belong to).
There have been times when the faith of the Church and also its moral life, came under attack or else the Church felt the need to regulate them.
This is done by way of Ecumenical Council and also by Local Council (and the laws of the latter can also be approved for the entire Church).
Also, individual Patriarchs can issue letters etc.
As Schmemann and others have said categorically, the authority of the BISHOP (meaning any bishop) is ABSOLUTE in the Church.
This is believed by both Orthodox and Catholics (and also any other Christians who hold to the hierarchy of "bishop, priest, deacon").
When our Bishop, Metropolitan or Patriarch teaches something, he is affirming the Apostolic Faith that the Councils expounded.
Whether one is Catholic or Orthodox, one accepts the teaching not because of the man who teaches, but because the Holy Spirit is using the hierarch to communicate to us living today what He wishes us to accept with our minds and hearts in terms of faith and moral practice.
From a very early period of Church history, three and then five patriarchates developed as great Christian centres, founded by the Apostles - Alexandria, Antioch, Rome, Constantinople and Jerusalem.
Union with these patriarchates meant that one was in union with the One, Holy Catholic and Apostolic Church of the New Testament, founded by our Lord, God and Saviour, Jesus Christ.
At Councils, as defined by the Fourth, the Bishop of Rome held a primacy of honour as first Patriarch in the Church.
This Petrine Primacy was what gave the Holy Orthodox and Catholic Church of Christ her unity - as Meyendorff has shown and quoted from sources to the same effect, as has Kallistos Ware.
Rome didn't involve itself jurisdictionally in the affairs of other Churches or other theologians/teachers - except in times of crisis, such as the iconoclast crisis and others before it.
As we see during the proceedings of the Sixth Council, Rome and her bishops are praised highly by the Eastern Fathers!
And one reason for that is that the Patriarchs of the East needed Rome as a referee in their dealings with the Byzantine Emperor who basically held sway over the Eastern Church (much like the Tsar of Russia did over the Russian Church in caesaro-papist fashion).
It was really only over the Filioque issue that provoked the schism between East and West that the East refused to recognize the Roman Pope as bearing the Primacy and the rest is "l'histoire" as they say.
Papal infallibility is therefore ONE way the Holy Spirit affirms the Apostolic Faith and defends it, as He hands it down to succeeding generations of Orthodox Catholic Christians.
The Ecumenical Council in union with the Pope is another.
And when my bishop teaches me something, I accept that without question, just as if the Pope were teaching it to me (hello, Vladyko!!).
If we feel that papal infallibility appears as too authoritarian etc., let us consider that the bishop's authority in general is absolute.
The Pope is the mouthpiece for the Church, when it comes to defining and defending faith and morals, he is where the "buck stops."
As St Augustine said, "Roma locuta, causa finita" (being a lawyer, I know you know what that means

).
And what is the reverse of papal infallibility - that the pope can teach error? And then, that the bishops can teach error?
As the Fathers taught, without the Bishop, there is no Church. The Bishop (metropolitan, patriarch or pope) is the foundation upon which the Church is built.
The Bishop is the successor of the Apostles, of St Peter himself.
But the Church has, from earliest times, always given a pre-eminence to the Bishop of Rome and the BIshops of Rome have always taken it upon themselves to teach the entire Church, to defend the Church against her enemies and to sacrifice their lives, as the many early papal HIeromartyrs did, rather than betray the Church.
I am in communion with the Pope of Rome because I believe that in so doing, I'm doing what the Church of the first thousand years did and acted toward that Hierarch.
That his teachings "ex cathedra" (meaning "when he has the intention to speak with the authority of Peter and the Apostles") are to be accepted as teachings that the Holy Spirit wishes us to accept.
And I find nothing here that is contrary to what Orthodoxy has always taught about the office and role of Bishop and Patriarch.
And also about the Petrine Minister of Rome.
Alex