Are your blog punished by google for posting dublicate content , and you are still searching for the reason , then check google webmaster tool for dublicate post,many blogs are punished by google for posting dublicate content , even if you have not done intentionally. this happen mainly because of images , when you use images in your blogs then attachment pages is created with same title.
Now to solve this we need to Remove Image Attachment Pages from Google and to tell google that we dont want to index attachment pages in google we only want to index images , to do this you can take help of plugin , Attachment page Redirect plugin will automatically 301 redirect links to the attachment page back to the post they are associated with .
