Continuity mistake: In the scene with Jinxers and the old neighbour lady are eating strawberries, the plate of strawberries is in front of Jinxers. It cuts to Julia again and back to Jinxers. The strawberries are now to the side on a different plate.
Continuity mistake: When they are all at the rehearsal dinner and they are all singing, once we have seen the picture of Julia with the beard and moustache, Grant's Dad puts his fork down and we hear it clink. Then in the next shot he puts a knife and a fork down on his plate.
Continuity mistake: In the beginning when Julia is dancing over the vent, you can see she is wearing black underwear. Later when she is sprayed with the hose and knocked over, she is wearing flowered underwear.
Continuity mistake: When Julia and Grant are at "A Restaurant", watch the necklace on her neck. It keeps moving position throughout the whole restaurant scene.