Audio problem: In the scene when Mud and his "dad" are getting ready for Celeste to come over, Mud bounces a basketball across a hardwood floor but it makes no sound.
Continuity mistake: At the beginning of the movie, Walter had braces, but as the movie goes on, you see him at camp with no braces on.
Grocery Checker: Can I see your ID? You gotta be 19 to buy this stuff.
Zach: No problem.
Grocery Checker: You were born in 1963?
Grocery Checker: And that would make you?
Grocery Checker: Wrong. It's 1994. That would make you 31.
Trish: Wrong! If he was born in 1963, and he's 21, then it's 1984! Uh.