At the beginning of the movie Rotti is looking at the pictures of his children doing things he disapproves of and his children are in the room but two seconds later when the doctor walks in to tell him he is terminally ill they are gone.
In the beginning of the movie where Shilo Wallace is in the grave yard hiding from the repo man, she is behind a head-stone. At one point (just after the Graverobber pulls the needle out of his pack and before he says "Lest it be you on the concrete below"), she leans on the tombstone and it moves.
The goof item below may give away important plot points.
Incorrectly regarded as goofs
When Blind Mag pulls out her eyes, you can see her eyes on her fingers but a moment later, it appears as though her eyes are not there. However, if you pay very close attention, you can see that her eyeballs slid off her nails.