The fact that Aishwarya Rai Bachchan was unceremoniously asked to walk out of Madhur Bhandarkar's Heroine and replaced by Kareena Kapoor after reports of her pregnancy, is not news anymore. What is now doing the rounds is that Aishwarya Rai is extremely upset with Kareena for accepting Heroine, a project which Ash had decided to finish post her maternity leave.
If sources are to be believed, Aishwarya Rai Bachchan is unhappy with Bebo's decision to do Heroine and has expressed her disappointment clearly.
The strain in the Kapoor-Bachchan relationship first came out in the open when the wedding of Abhishek Bachchan and Karisma Kapoor was called off.
Grapevine also has it that Abhishek Bachchan had later refused to work with Kareena Kapoor in Dostana as he was uncomfortable facing the camera with her. Karan Johar had hence approached Priyanka Chopra for the role. The same thing happened with Prakash Mehra's Delhi 6 in which Kareena Kapoor was replaced by Sonam Kapoor.
It seems like it's 'revenge time' for Kareena Kapoor. Now that Bebo's career is flying high, the actress seems to be in no mood to apologize the Bachchan's!
Source:http://entertainment.oneindia.in/bollywood/gupshup/2011/kareena-kapoor-upsets-aishwarya-rai-bachchan-070911.html