Audio problem: When Ralph and Randy are in line waiting for Santa, if you listen closely Santa keeps repeating the same words like "And what do you want for Christmas, Billy?" "get him off my lap," "Santa can't wait all night let's go!" "HO HO HO!" but in the exact same tone, the child and Randy's screaming is also on repeat too.
Audio problem: When Ralphie's father opens the crate containing the leg lamp, he says, "Well, it could be anything." Then his mother says, "Maybe they forgot" without moving her lips. Obviously dubbed in later.
Audio problem: When the leg lamp breaks, it makes a crashing sound like breaking glass, but then the wife asks "Jealous of a plastic lamp?" and it's obvious that the lamp is indeed soft plastic.