Audio problem: Near the end of the movie when the band is playing the song for the guy in the limo when shes singing the chorus to the song the voice changes from the original song to her voice.
Continuity mistake: When the group are in the diner and Garth notices his "dream girl" stacking plates of pie and cake in the display case, she can be seen placing a plate on an empty tray, then the camera returns to Garth. Moments later the camera is returned to his dream girl and the tray is again empty. (00:10:05)
Continuity mistake: After Wayne is finished using the cue cards for Noah Vanderhoff's interview, they cut to commercial. Wayne grips the stack of cards with two hands initially, but when the shot changes to Terry saying, "We're at commercial," Wayne is only using his left hand. (01:07:50)ryguy_1983
Deliberate mistake: When Wayne begins playing the "Excalibur" guitar, the clerk stops him and directs him to a "No Stairway to Heaven" sign. The problem is that the guitar riff Wayne started playing sounded nothing like "Stairway to Heaven" so the clerk had no reason to interrupt him. Evidently the intro to "Stairway" was actually played in the theatrical version of the film, but its exclusion in the home video release makes the scene rather dubious.Phaneron
Continuity mistake: When Benjamin is talking to Wayne and Garth about giving Vanderhoff a spot on the show in the first scene. On the left side of the end of the table there is a tray of nachos with dip and different kinds of drinks, then in the next scene when Wayne talks to Garth about selling out the nachos with dip are on the right side of the table and the drinks are gone. (00:47:47)