Plot Hole (Spoilers)

I just watched this movie and i thought it was way better than what i expected. I just found something curious.

Sorry for my english...
We get to know why the Pumpkinhead exist, and who he is. **Spoilers** When the Pumpkinhead wake up, he start by killing the kids who were making fun of him when he was young and deformed. I think he do that because it's the first thing on his list, you know, the things he have to do. We learn that after he kill all of those kids, he will be on the trace of the other kids who kill the witch. So it's like something he has to do before! Now, what i don't understand is why Pumpkinhead haven't kill thoses kid back in the first movie when he have the chance ** end of Spoilers**

I know it's just a movie and maybe it's not related that much on the first one, but it's just a plot hole or a little mistake the maker have make...