I need help with winterboard on iphone 3g?

I need help with winterboard, my iphone 3g is currently jailbroken and at version 3.0. Today, I experimented with winterboard and i saw this keyboard theme that i was interested in called Macbook Black. So i installed it, and went into winterboard and checked it. But when i went into my text messages to see if my keyboard’s appearance changed, it was still the same default keyboard. PLEASE HELP! i really want the keyboard theme!