I think it was like the sound in heat, but you both seem to have found that possibility listed - so, I guess, that's the answer - it's an alternative pronunciation. Thanks. In a way it seems to me maybe more logical, because it comes from Latin pejor, meaning worse plus suffixe - ative, and this version focusses more on the pejor bit rather than "jorative"
Hmm, I'm not so sure about he Latin logic, orlando. If that were significant, we'd have to apply it to majority, minority, paternity, ... and a whole host of other words that have the stress on the second syllable.
I've never heard pejorative with the stress other than on -jor-, but if some dictionaries list the other possibility I suppose it must exist.