Continuity mistake: In the scene where Ben Stiller, Patricia Arquette and Tea Leoni go to visit Ben's adoptive parents, Mary Tyler Moore and George Segal. Mary and George get into an argument and Mary picks up the 3/4 Brie cheese wheel and chases George into the other room. Cut to Ben yelling at them. Then back to them, the brie wheel now much smaller. Then cut again and the brie wheel is back to 3/4 size when they return to the living room.
Continuity mistake: During the scene at Ben's adoptive parent's house, Ben Stiller and Tea Leoni are sitting on a couch talking to Mary Tyler Moore and George Segal. Watch Patricia Arquette w/baby in the background between Ben and Tea. What she's eating (cracker or cheese) changes size between shots and when she says, "They killed Art Sacheim?" it completely disappears and reappears in the next shot.