Upgrading your WordPress blog to the latest version, you can notice that images are now automatically made into hyperlinks to themselves. This is not quite ok in special when you are working with small size images. Here is a quick tip to fix the bug, and avoid it on future upgrades.

Open your function.php file from theme folder, and:

Add this code to set to “none” the links for images:
[code='php']update_option('image_default_link_type' , '');[/code]

Add this code to make like default option, link of images to the post:
[code='php']update_option('image_default_link_type' , 'post');[/code]