That is because it is impossible for you to discuss a Catholic teaching on your own terms. The Church has precise definitions on what She believes. If you don't relate your discussion to those definitions, but rather a definition of your own making, you will only be arguing against a figment of your imagination, not true Catholic teaching. Witness Havoc's inane objections to the term Theotokos(i.e. "How can Mary be God's mother? That would mean that she existed before God."). He is arguing against something which is not is not a part of, and is indeed directly contrary to, the definition of Theotokos as taught by the Council of Ephesus. There is only one faith that the Catholic Church holds. A faith which has been preserved and passed on since the Apostles.
The same cannot, sadly, be said of Protestantism. Whether it is justification, the Sacraments, the nature of the Church, the authority of said Church, Christology, morality, or even the nature of Sola Scriptura, they all mean different things to different groups of Protestants. The Lutherans say one thing, the Calvinists another, the Anglicans another, the Baptists another, the non-denominational denominationalists yet another, etc... Will you say that they are all wrong and you are right, as Havoc does? That is what they each say about you.
For you to proclaim the "true" definition of Sola Scriptura is, no offense, a bit disingenuous for there are as many definitions as there are Protestants denominations. They may be very similar, but they can be subtly different from each other. Be that as it may, in the end Sola Scriptura, in whatever form, ultimately leads to a radical individualism that has never been a part of the historic Christian faith.
Pray for JP II