Continuity mistake: In the end Montoya fires the gun then presses it to his neck to cauterize the wound. However if you watch he never touches the gun to his neck.
Continuity mistake: In the first part of the movie, when Jack and Montoya returned to the Sun God Motel for burning their friends, there is a wound in Jack's neck. But in the next shot it is not there.
Continuity mistake: At the beginning, after looking at the nest through the binoculars, you see Daniel Baldwin climb into the driver's seat of the armored van. But, when they arrive at the house, he gets out of the jeep.
Continuity mistake: When Jack, Katrina and the others get to the monastery where the cross was hidden, the sun changes between shots.
Continuity mistake: Towards the end when Montoya tells Jack that a master vampire can't be killed at night, the sun changes from daylight to dark then back again.
Continuity mistake: When Montoya saves Jack from the cross, Jack moves his head down to the left, then in the next shot it's to the right.