Little Big Planet, can't move onto the next part of the level?

I bought this game a matter of hours ago and therefore right now I'm on the introduction level sort of thing. I have just got up to the part where it has the sackboy in the box and says introducing above it. However when I walk up the stairs and try to move on my personalised sackboy dissappeas and there is something that counts down from 5, I have tried restarting the level loads of times and it just keeps on doing it at the same point on the leel over and over again and when I leave it to finish the countdown the whole game just sticks on the introducing part and my sackboy dissapears altogether.