Continuity mistake: When Carly wipes the dust off the mirror in the wax museum, the initial double hand swipe is repeated in the next shot. (00:38:00)
Continuity mistake: Elisha Cuthbert is a foot shorter than Jared Padalecki, so they stacked blocks under her shoes to make her appear taller (as seen in one of the extras). However, in full body shots there is nothing under her feet and she's much shorter than those shots when you can't see her feet.
Factual error: According to netstate.com the average monthly high in the state of Louisiana is 93.3 degrees F (34.05 degrees C) with summer months often exceeding 100 degrees F (37.77 degrees C), making it impossible for a functional multi-story wax structure to remain functional for any extended period of time, regardless of wax content.
Continuity mistake: When Carly locks herself in the truck, the owner throws to the ground the box holding the fan belt and a few other things, right beside the driver's side of the truck. In the next exterior shot, there is nothing on the ground. (00:50:50)
Continuity mistake: After Vincent has stabbed Blake in the neck at the campsite, a terrified Paige runs for her life and tries to hide in a large dark building (the abandoned sugar mill). Whilst she is running through dark hallways, she passes through patches of moonlight and we see that her eyes are dry, and her face doesn't exactly show an expression of terror (Hilton's poor acting perhaps?). However, seconds later, she crouches down to hide and the lights are turned on, and we see that she is crying and tears are streamed across her face, yet she was not sobbing nor crying before she crouched down, merely screaming and panting. Immediately afterwards, when she is searching through a box of discarded cellphones, her face is once again dry and her eyes not red, and it remains dry throughout the rest of the scene, despite her not having wiped her face at all (including the scene of her face right before Vincent impales her: her mascara is completely untouched). (01:11:20 - 01:11:50)