Street Fighter IV - Tips for an old SF2 fan

[Zen]

I understand the advantages for the kara throw but I cant seem to pull them off on demand on an actual fight, last game i really tried was, third strike, but i only got it like once every 8 tries or so, the rest i would just do the attack i was trying to cancel, so i let it go. Training mode, awesome, actual match, no way.... its like now in 4, ryu's shoryu ->FADC -> Ultra, I can do it on wake up, but not in a combo for some reason.