Continuity mistake: In the scene where grandpa is attempting to ship his grandson to his dad in a cardboard box, grandpa says to the two ladies who are objecting to his requests "well give me a pen, and we'll write FRAGILE on it." Shortly before he says that, the box already says "FRAGILE" on the right hand side, and then 2 seconds later the writing has disappeared. (00:31:10 - 00:32:15)
Continuity mistake: Near the end of the film when Robert De Niro gets to make out with the college girl, the switches between camera shots show his shirt off and then subsequently back on again.