Good game, but I can't get full version. – Coaster Frenzy Review

Like the title says, I like the game; I had the full version on my first iPod. But, every time I go to click the "Full Version" button, on my new iPod, I'm sent back to my home screen. I'm probably just not seeing how to do it correctly, but if anybody knows how to fix it...? Could you please help?
Review by TheArmoredDragon on Coaster Frenzy.