Continuity mistake: When Jiminy Cricket (The Ghost of Christmas Past) jumps on to Scrooge's bedside table, the time on the alarm clock reads 2:00. In the next shot, when the curtains move and Scrooge hears the dinging, the time reads 1:00, and when we return to Jiminy Cricket in the next shot, the time reads 2:00.
Marley: Ebenezer? Remember when I was alive I robbed from widows and swindled the poor?
Scrooge: Yes, and all in the same day. Oh, you had class, Jacob.
Marley: Ha-yuk, yup... Er, no, no! I was wrong. And so, as punishment, I'm forced to carry these heavy chains for eternity! Maybe even longer.
Scrooge: Yes, Isabelle?
Belle: My eyes are closed, my lips are puckered, and I'm standing under the mistletoe.
Scrooge: You're also standing on my foot.
Scrooge: Bah humbug.