That appears to be behind the grudge of some in the Russian Orthodox Church in Russia toward the Roman Catholic Church. Check out the story from today's New York Times here.
One other comment: The charge of the Church from Christ is to "make disciples," to actively help people know Jesus Christ so that they too can become His followers. (Matthew 28:16-20) I should think that the Orthodox leaders in Russia would rejoice when people who hadn't known Christ come to follow Him through the ministries of the Roman Church. Those of us in the Church--whatever our denominational flavor--are, after all, on the same team.