Audio problem: When Mrs. Hudson finds a package for Sherlock instructing him to open it before the trial, she says "I never even heard anyone knocking" whilst handing it to Watson, but the line appears to have been dubbed over as her lips don't match up with the dialogue.
Audio problem: On the Titanic, whilst Mrs. Hudson is tying Watson to the cogs, she says "I'll be on my way to America by the time the bomb explodes" shortly before she leaves him, but the movements of her lips do not match up with the dialogue heard coming out of her mouth, revealing that the line was poorly dubbed over.