Is my Little Big Planet game slow?

I recently bought Little Big Planet (the first one, pre-owned) and because i don't have a ps3 myself my friend and i share the game and play a 2-player game. The only thing is the game is kind of difficult to play...what should be easy jumping up on to ledges and whatnot is actually kind of difficult, it can sometimes take several tries just to jump onto a little sack or something. and theres always about a second or two delay before i jump...is that normal? is it because we are playing with two people? do you get used to it eventually? it's not a big deal it's just not a smooth gameplay and it's making it difficult, and i've never played a playstation game before so i don't know if this is normal for their games. thanks :)