let them flash the phone, that usually solves these kinda problems with Samsung phones

So I came to canada from Australia today and had gotten a code from virgin mobile to unlock my phone for use here. I went to a rogers mobile store (the only company localy I can use for my particualr sim card apparantly) and bought a sim card and registered my phone. the clerk instructed me to turn off my phone and then turn it back on. I did so and my phone would boot up, display the home page for several seconds (pushing any buttong results in nothing) and then shutting down then repeating the process over and over by itself.

I can see when the main page loads that I have reception and even had the phone alert me of a txt message (pressumably a welcome message from rogers)

Anyone have any experinces like this or know where to start in resolving it.