Revealing mistake: When Jessica Alba is getting up from the bed after sex, you can see the adhesive modesty patch covering her chest. (00:36:15)
Revealing mistake: When Gypsy tries to hit Helen with her weapon, she misses and hits a table instead, causing one of its leg to break off. However before the weapon even hits the table you can see the leg coming off from the table; obviously being pulled off.
Revealing mistake: Mike putts successfully against his opponent and decides to celebrate. He does so by juggling a golf ball; too bad it's a poorly textured CGI golf ball that does not even appear rigid. (01:02:05)
Revealing mistake: Near the end of the DVD version, one of the main characters (I think Deke) is chainsawing the spiders. In two of the shots, you can see the man's legs through the spider.
Revealing mistake: When Rolfe is walking down the hallway to Sally's apartment, there is an orb where the hallway is lighter colored and his legs seem to jump and undulate due to the special effect used to hide the fact that the actor is actually full-sized, walking on his knees.
Revealing mistake: The first night Ben brings Andie home, he starts the music on the CD player, but no CDs are spinning at all. Yet, the music still plays. He also changes the track mid-scene, and still no CD is spinning.
Revealing mistake: When Otis cuts off Bill's hand, you can see it's a fake hand because it turns sideways after the first swing of the axe.
Revealing mistake: In the scene where Chris is hiding under the bed with Eliza Dushku and the mountain men bring in the corpse of the red-haired girl who was nearly decapitated by the barbed wire and dump it on the floor, the 'corpse' is still breathing.
Revealing mistake: When Henry is running to the injured civilian there is a shot where you can see his kneepad under his trousers. (00:46:20)
Revealing mistake: When Kirk Douglas returns from his run in the park the door attendant calls him "Mr. Douglas" and then corrects himself in the next sentence after Kirk waves him off.
Revealing mistake: One of the accountants' computers has no power cord attached to it.
Revealing mistake: When Hulk rips the turret off the tank and swings it around in the desert has a solid base. This is correct for a model but not for a real tank which has a hollow turret for the tank captain to stand up from the bottom of the tank through the turret and look out the top.
Revealing mistake: When walking across a curved path, you can see Judy step off the floor where he was supposed to walk.
Revealing mistake: When Tara Reid is being slapped around, pushed and tossed out of the cabin, we can see that it's a stunt double, by the dark hair at the front where the white wig has slipped back, exposing the double's dark hair.