having no scriptural warrant
There are many teachings both Catholic and Protestant that are Extra-Biblical
because Rome does not stand on Scripture alone as the infallible word of God.
This Holy Bible is like no other book, because no other book has God for its principal author
-Father Jaime Pazat De Lys (A very conservative priest)
While you won't find anyone reasonable in Rome who would say the original Bible isn't inerrant as it is the word of God inspired through the blessed writers- Rome is weary to proclaim that all Bibles are infallible for one simple reasons- translations.
Hebrew -> Greek -> Latin -> German -> English -> tons of translations (NIV, NKJV, LB, NASB...etc)
The question begs itself: were the translators of the Bible through all these stages given the inspiration and blessing of God? Rome doesn't think so- especially with such bibles as the NIV (My priest jokingly calls it the Nearly Inspired Version) which has come under attack by many biblical scholars (both protestant and catholic) for some questionable translations. Things get lost in translation- that's quite easy to accept, especially being a Latin student- and you can't except for some versions to be infallible. The "Modern" NIV version that briefly came out that made the bible politically correct comes to mind (they refer to God as he/she, say human kind, etc...) <img src="/forum/images/graemlins/Banghead.gif" alt="" />
Also, a less subtle change came from the translation from the Vulgate to German by Martin Luther when he added the word "Alone" to "Being therefore justified by faith"
That's a pretty big change right there.