Agreed . . . the old preacher used to scare the shit out of me as well. And the "tequila worm" sequence is one of the most disturbing things ever filmed, IMO.
Don't know about a curse, but I know the chick who played the older sister in the first film was murdered by her boyfriend.
Sad stuff.
J.N.
http://members.tripod.com/~NEWMANATOR/index.html