Bug while Customizing Search Layout

Bug while Customizing Search Layout

I am trying to add Mpbile phone in the grid when search is performed.Right now in my view I see Lead Name,company,Phone,email and I went to Setup->Cuztomization->Search Layouts->Selected the Module Leads

and Clicked Edit and Checked on the Mobile field and clicked Save. But I still donot see the Mobile field in the result grid

Am I missing anything or is this a bug in the system? Please help