Continuity mistake: In the episode "23" when Lorraine, Karen and Will are talking in the entrance to the church, before Stan's funeral, there is a signing book with a pen laying on it. But in one shot the pen has jumped back into the pen holder. It's back to laying on the book in the following shots.
Continuity mistake: In the episode "24" when Rosario brings the huge popcorn can in, which has Stan's ashes in it for them to scatter, she puts it down in front of the table, at about the center of it. In following shots the location of the can has changed, moving more to the left / right, etc.