Revealing mistake: In the end at the airport, when Ricky walks up to the line to give his part of the story, you can clearly see a light reflecting off the black cap on Ricky's tooth, to make it look like he has lost one. (01:14:40)
Revealing mistake: In the scene when Janey falls through the steps, you can see that the double pulls herself into a small room at the bottom of the hole to keep her from getting hit by the falling items which are the second part of the falling joke. (00:41:00)
Revealing mistake: When Janey falls through the stairs you can tell that it is a stunt double because she's really buff, unlike Chyler Leigh. (00:37:35)
Answer: The song is called "Yoo Hoo" by Imperial Teen. The same song plays in Jawbreaker when Rose McGowan is leading her friends down the hall, which is of course, the scene that Not Another Teen Movie is mimicking.