Help activating iPhone in Puerto Rico (AT&T)

I live in Puerto Rico and recieved my iPhone yesterday from a relative in FL. We have AT&T service just like in the states including EDGE and 3G (which the iPhone doesn't use). There have been reports o people who activated in the states using the iPhone in the island succesfully with no problem. I have tried to activate using my local phone number (787) and my address but the activation fails. Is there any workaround? Including iPhone or AT&T related. Any help will be greatly appreciated. Right now i have a very good looking and expensive paper weight in my house. :D