Continuity mistake: When Tony is stuck in the tunnel in the prison and is talking to Wolf, there are still several feet of tunnel ahead of him before the end of the tunnel. But when Wolf gives him a push, he is shown coming right out of the tunnel's end.
Plot hole: When Wolf and Tony find Virginia in the Huntsman's tree house, she tells them that he chained her up, so she can't go downstairs and open the door from the inside. However, after Wolf climbs her hair and enters through the window, the two of them walk down the stairs without any chains stopping her. They couldn't have cut her free with the magic ax because Tony was holding it, and he was downstairs by the door.
Audio problem: When the Queen is speaking to the Troll King for a second time in the mirror, she wraps up discussion with him and in the next shot she walks over to her mirror and says, "Mirror, talk to me, why haven't you found Windell yet?" The Queen's mouth moves ahead of the actual voice.
Continuity mistake: When Wolf and Virginia are talking in the Swamp, a piece of string is on Virginia's shoulder. It disappears/reappears in the following shots.
Continuity mistake: When the Gypsy takes Virginia's hair, she spreads it apart before putting it in the potion. Later, when she goes back to the same potion to curse Virginia, the hair is clumped together in a single lock, not separated.
Other mistake: The second time Virginia goes down the slide in the 9th Kingdom, you can see that it is a stunt double hurrying to get off at the end.
Revealing mistake: In the close-ups of the elves during the Coronation Ball, you can see the fishing wire used to attach their wings to their backs.
Other mistake: When Virginia places the flower on the dead Queen's hand and kisses her forehead, you can see the Queen take a breath.
Other mistake: In the boat with the golden fish, the sign next to the fish says that you must stick your finger in the fish's mouth, then turn around until you "face south". Later, Tony sticks his finger in the fish's mouth and doesn't make any turning motion, yet he still gets the golden touch ability.
Factual error: When Wolf is starting to turn and the Queen contacts him, after he storms off, in the daylight in the distant background on top of the hill electricity towers can be seen.
Revealing mistake: In the close-ups of the Queen as she dies, you can see the line of her wig on her forehead.
Audio problem: During the shepherdess competition, when Sally says that Virginia doesn't have a dog, there is a shot of Sally while she is still saying the words, but her lips aren't moving. She just makes a small smile.
Other mistake: After Virginia wins the mirror in the shepherdess competition, she and Tony are in the barn and they hear Sally screaming. Immediately after her screams are heard, a man runs into town and says that she has been murdered. Between the screams and the man announcing the murder, there wasn't enough time for Sally to have screamed at her grandfather, been killed by him, and then been discovered dead.
Answer: They're both hearing things that they miss. Tony misses being back in his own world, so he hears a song that he knows from there. Virginia hears a wolf howling because she misses Wolf.