jmcarrillo -- you already have one string on this and had the question answered: Looking for OS 5
If I were placing my bets on who is correct, I would go with the answers you got from JSanders and John Clark on the other string: data plan required to upgrade to 5.0; new requirement since around the first of the year.
Edit: I apologize. You actually started this string before the other one. Answers there still stand.