The story goes like this; Amisha's character in the film required her to play the role of a flirtatious woman, who would go to any length for money. The actress obviously found the role to be on the verge of being crass.
Add to this the fact that there were a few steamy scenes with Tennis star Paes which made Amisha very uncomfortable. It required her to show a lot of skin and the character she plays is extremely unapologetic about the whole thing. Amisha was supposed to talk in a very bold language and in short her whole look was one of a girl who is vulgar and forthright. She was not ok about it, in fact she realised that it was completely not her. When Ashok Kohli, narrated the role, the actress realised instantly that she cannot do it.
Considering that she was not up to doing some rather crucial scenes in the film. Amisha has walked out of the film. Now it's Leander who has to play his game right to woo another actress into the project, who can further woo him in the film.