The original title of the film was "Kyon! Ho Gaya Na Pyar..." But the director felt the word pyar (love) was very common and used too often in Hindi films. So he restricted his movies title, by removing the word pyar from the movie.
While in production the movie got delayed because of the accidents the main lead had to face on the sets of their other movies, 'Vivek Oberoi' in Yuva (2004) and Aishwarya Rai Bachchan in Khakee (2004)
Amitabh Bachchan screen name is never mentioned throughout the entire film, he is referred as uncle in the film. However, at script stage, his name was Raj Chauhan.
When Diya and Arjun go to Vinay's party, Arjun is wearing his necklace. When he goes to Diya's house she has the necklace, although Arjun couldn't have given it to her because she left while he was asleep.