Visible crew/equipment: Sometimes, especially at night, you can see the lights of the equipment reflect off of Tony's glasses. We know this isn't the moon or a car light because for one thing it's the wrong shape and when Rudolf is sucking blood out of the cow there is no moon or car nearby. So there is only one place the light could have come from, and that would be the crew equipment.
The Little Vampire (2000)
1 visible crew/equipment mistake - chronological order
Directed by: Uli Edel
Starring: Richard E. Grant, Alice Krige, Jim Carter, Jonathan Lipnicki, Rollo Weeks
Audio problem: When Tony goes down to help Rudoplh after he tries to fly out of the window, Tony asks him if he's okay and you can hear Rudoplh saying "Do I look it?" but his lips never move.
Tony: Bed for the undead?
Trivia: The vampire's last name was Sackville-Bagg - Bilbo Baggins' relations in The Lord of the Rings were the Sackville-Bagginses.