As I may have mentioned before, my wife (let's call her Maude) belongs to one of the Eastern Orthodox churches. For her, church is inextricably tied in with her ethnicity, which I suspect is the case for most people outside of America. This makes the whole idea of changing religions much more problematic. For her, I suspect it would be like losing a part of her identity.
This notwithstanding, she is shopping around for other denominations. Why? Because her church does not recognize our marriage. Even though we were married in an Orthodox church, it was done by an unorthodox priest (ironically) who didn't require me to get rebaptized. As far as the official church is concerned, we are living in sin, and all basically because they don't consider me a Christian.
I have no problem with them not recognizing my baptism as valid. We, after all, don't consider theirs to be valid either. But it boggles the mind that a Church would refuse to recognize a marriage solemnized in one of their sister churches. (To be fair, there are a million different permutations of Eastern Orthodoxy, and we were married in a different branch than that to which my wife belongs.)
It seems odd to me that they don't recognize any marriages except those between Mainstream Christians to be valid. As more and more people inter-marry outside their ethnicity, this seems like a good way to lose members fast.