How it possible ?

whatever theme i add in my blog suppose http://www.A.com, i did not seen a link to edit the current post, if a user is logged in and allowed to edit the post.

but when i install same themes in my another wp blog suppose http://www.B.com, the button ‘edit’ will seen.

any suggestion why i did not seen the edit button in http://www.A.com

is there is any installation bug?

Thanks