So let's say you turn on your ps3 and sit down to play LBP2. All of a sudden when you get to your pod you find that there's a planet inside your pod and you can't do anything about it! This might definitely be frustrating for anyone who just wants to start playing right away. All you have to do is restart your ps3 and open the game one more time and the glitch will be gone allowing you to continue your little big planet adventure. So for all of you, do not panic like I did, just restart! Hope this helps =)
P.S: Below is a picture of what it will look like, this one wasn't taken by me since I didn't have a camera at the moment it happened, but I found this picture on google images and it looks exactly like what happened to me.