A pope is infallible only when he speaks ex cathedra, addressing something to the whole chuch regarding faith and morals,using the language of infalliblity.
All of thses criterias must be present for him to be infallible.
And... He is infallible only when he defines something that was always believed by the church.
[/quote]For the spirit of Jesus is not promised to the succesor of Peter that he might make new dogmas, but that he may declare what was believe by the Church from the begginig.