Audio problem: During "Breaking Free" (near the end), the audio has both Gabriella and Troy singing the line "You know the world can see us," but Gabriella's mouth does not move until the word "can." (01:29:25)
Audio problem: In "What I've Been Looking For", when Sharpay sings the last verse the first time around, listen closely as Ryan takes away the microphone. Her voice remains the same volume, and does not get any quieter as Ryan pulls away the microphone.
Audio problem: When Gabriella is singing "When There Was Me and You", when she sings the line "Like I could Sing Along", notice her mouth doesn't move.
Audio problem: When Troy and Gabriella are singing "Breaking Free" for the last time, Gabriella moves her mic away from her mouth numerous times, yet her voice never gets quieter.
Audio problem: In "We're All in this Together", you can hear either Troy or Gabriella's voice singing background, not matching the others' lyrics, but their lips are moving to the same words as all the others.
Audio problem: After "Get'cha Head in the Game", Troy shoots one final basketball. When it bounces on the ground, the sound is slightly delayed.
Answer: I'm not positive, but that is what I've always assumed.