Audio problem: While Romeo and Juliet are kissing on the balcony, Juliet is speaking while canoodling at one point, but then she turns her head and her lips are not moving.
Audio problem: The choirboys sing throughout Juliet's funeral. There are also four flute players standing on a rise over her body at the tomb's entrance. However, no notes can be heard from any instrument even though they all give the appearance of playing. In a subsequent shot, one of the musicians does not even have his instrument up to his mouth while another one stops playing before the scene ends and is just standing there.
Answer: Olivia Hussey was born April 17, 1951 so she was probably still 16 when the film was being made, but 17 when it was released in 1968. Leonard Whiting was born June 30, 1950 - almost a year older than Olivia.
Myridon