Yeh.. THC wen metabolised in the liver turns into a more powerful and potent psyhcoatctive form of THC (can't remember the name... sorry). But every single person handles it completley differenlty.. some people hallucinate, others feel less than if they smoked.

BTW its a load of shit that weed doesn't make you hallucinate.. Those people are just differnent than other people and may not be as sensitive to THC as others. I personally have hallucinated many times (although not intense) while smoking weed.