Shah Rukh Khan was the original pick to play DJ, but the shooting for the film was in Delhi, and Khan was forced to decline because he was shooting Paheli (2005) at the time, and did not want to conflict schedules.
Arjun Rampal was signed to do the film, but was irritated with director, Rakeysh Omprakash Mehra's indecisiveness about what he wanted to do with the characters and the script. He called him "very confused" and "unprofessional" and dropped out. Arjun Rampal also stated his regret in even agreeing to do the film in that he lost a lot of good work in the three months he spent committed to it.
During one of the flashback sequences - set prior to 1947, the historical characters are on a roof of a building. In the distance is another large building, and, on its roof, is a large satellite dish.
In the scene where Sue says 'Undher say awaaz aye gee' and the Sukhi burps, Karan throws his cigarette on the floor and steps on it (you hear him do it). Then in the very next shot he does it all over again and the 'under say awaaz' scene is still going on.