In the opening scene when Scotty walks in on his boss and his girlfriend in bed, his girlfriend is completely naked, but in the next shot, when she gets out of bed, she has her dress around her stomach.
At the end, when Scotty and Jeanie are shown walking from the front, she is on his right. When they are shown from the back, she is now on his left side.
Kenny the reluctant surfer enters the water with yellow leggings, long frizzy blonde hair, and a bare upper body, but moments later after Jeanne provides a big wave that wipes him out, the surfer shown at a distance with his voiceover is wearing a blue leotard with white arms, no leggings, and short dark hair.
When Jeanie throws the pizza at the TV, it leaves a big greasy stain/mark on the screen.
But afterwards when she gets up to leave, there's no mark on the screen at all.
The writing on the note left by Cindy (Scotty's girlfriend) at the beginning of the PG-13 edit of the film doesn't match her voiceover reading.
Scotty (Dean Cameron) is desperate to save Jeanie (Amy Dolenz) and he asks Mystic (Vincent Schiavelli) for help. Mystic tells him he has five seconds left to speak to her or she will be gone forever. He waits eighteen seconds before speaking to her, and yet she is saved.