At the very end, when Frank is talking to Ed right before the ceremony, Frank's hair is very gray. When they walk down the aisle, Frank's hair is very brown, not much hint of gray.
At the very end during the wedding ceremony, characters sitting behind Frank & Susan on the right hand side of the aisle are a different set of people while shot from the camera behind, while Frank walks his daughter.
The length of Frank's cigarette changes in his scene with Buddy in the motel room.
Ryan complains that his wife sets his clocks forward to give him more time but then says it actually gives him less time. Moving a clock forward would make Ryan arrive places ten minutes EARLY, so the wife is right and Ryan (and the writers) are wrong. e.g. His watch would say 9:00 when it was really 8:50.