There seems to be a lot of general confusion about what "infallible" actually means in this case, partly because it was only really defined 150 years ago. The only time a statement by a pope is infallible is when it is an explicitly universal teaching made on a matter of faith and/or morals.

Only two such statements have been made in the last two hundred years, namely those on the Immaculate Conception and the Assumption of Mary. The canonization of a saint is also generally considered an infallible declaration. Ecumenical councils can also define infallible teachings, provided, again, that they meet the criteria I mentioned above.

The pope certainly has teaching authority when not meeting those criteria; he just isn't considered infallible.

EDIT: Here's the Wikipedia article on it. It seems pretty balanced:

https://en.wikipedia.org/wiki/Papal_infallibility