Jailbroke my old iPhone?

Upgrade to iPhone 4 so got the network unlocked on my old iPhone 3g and decided to jailbreak it had nothing to lose! So I downloaded redsn0w etc. got all that done got cydia on the phone but when I go into change the sms bubbles it does nothing even when Iv selected the color resprung it and rebooted? Iv downloaded winterboard do I need to download something else? Any help would be great never done this before not planning on doing it with my new iPhone just trying it out on my old one :)