The infallible Bible is the original text taught and preserved. The "versions" come about through changes in language and translation (or outright heresy as in the case of the "homosexual" bible et al). It's not that the old text changes, rather our modern language is evolving and it can take different words to express the same thought. Unfortunately, some times these different words are then interpreted differently...
What of the books redacted by the Church throughout the centuries? Are they still part of the Bible, but we just don’t care much for them?
Good explanation. And to add to it, it should be noted that nearly all commonly-available (KJV, NKJV, NIV, NASB, and so forth) translations/transliterations do not change the original meaning of the original language. This is critical. Any translation/transliteration that changes the original meaning is worthless and invalid.