Hi Everyone, I just got my new Iphone today!

I just set up an account and got a sim from Rogers today and so far it works great except for text messaging. Is there something I need to set up to get text messaging to work?
If I go to rogers.com/sms, I can send a text message to my phone easily but when my friend tries to text me or I try to text out, it fails.
oh ya, I did pay for the text messaging feature too.