Question about the Sookie Stackhouse series?

I just finished reading a scene from Club Dead by Charlaine Harris, and I was wondering about Lorena. If my memory serves me correctly, the author established that when a vampire is staked, they explode in blood and guts and everything. That's what happen to Long Shadow, I think his name was. If that's true, why didn't Lorena do the same when Sookie got attacked in the garage and staked Lorena? Just wondering! Thanks guys!