That's patently incorrect. Show your source for such outlandish comments.
CAFTA does have plenty to do with immigration. The post in question I believe refered to Rep. Clay Shaw that said, let us not tie the hands of those negotiating for the United States by prohibiting them from negotiating immigration provisions."
"Cross-Border Trade in Services
http://www.ustr.gov/Trade_Agreements/Bilateral/CAFTA/CAFTA-DR_Final_Texts/Section_Index.html