In the scene where Shah Rukh Khan and Kajol are stuck in the train compartment, Kajol's suitcase bursts open and she hurriedly stuffs her clothes back into it.
When Shah Rukh sits on the compartment floor, there is clearly nothing behind or underneath him. But in the very next scene, he pulls out Kajol's bra from under him.
Before the song "Tujhe dekha to yeh jana..", Simran is standing in a field of green grass. A shot later she starts running from a field of yellow flowers.
When Raj and Simran's mom had a word when Simran's Mom catches both of them she had a different dress and when she call them up in room and Raj had his conversation with her she has a different one.
During the climax, the railway station where Raj and Kuljit have a fight is shown to be 'Apta' (as seen on the signboard). Apta is a small station near Mumbai and is more than 1700 km away from Punjab where the plot is based.