Welcome 2 Karachi has not exactly got off to a welcoming start. Irrfan Khan, one of the main leads of the film has officially walked out of the project leaving producer Vashu Bhagnani in a lurch. Irrfan who was supposed to fly to London to shoot for the first leg of the film backed out at the last moment. While the rest of the cast and crew including Vashu and Arshad Warsi (who is the other male lead) are in London currently, the backing out of Irrfan at the eleventh hour has thrown the shooting schedule out of gear. An insider we spoke to says that Irrfan backed out of the project over certain creative differences that cropped up between him and Vashu. Vashu meanwhile expressed his shock over Irrfan's sudden exit. Sources close to the Vashu indicate that as of now the producer is not sure if he should be returning back to Mumbai or continue shooting there. For the moment, the makers are grappling to find the right replacement for Irrfan Khan. The mahurat shot of the film was launched amidst immense fanfare last week. What one couldn't help noticing then was the aloofness of Irrfan. While Arshad sounded gung ho about the project, Irrfan kept a low profile and displayed lack of enthusiasm. Was Irrfan already displeased right from Day One. Was he just putting up a brave front? Only Irrfan can answer that. The actor remained unavailable for comment.