I don't agree with hyperdox fellow, I agree with the Church, but he's made me think of a hypothetical situation. What should someone do if he divorces, remarries, starts a family with his second wife, and then converts? That is, he isn't Catholic to begin with, and then after starting a family with his second wife, finally becomes Catholic. Would he have to put his second wife away, while attempting to raise his children properly? That would be sad for the children.
And let's say his second wife doesn't agree, and so divorces him, and most likely gets the children, who would then not be raised Catholic. In these sorts of circuмstances is it a man's primary duty to rectify his own standing in the Church, and let the other chips fall where they may?