Media redirect propblem

Hello, I am new  in site building, so decided to to use your plugin on its website, the site have layouta photo blog, to be comfortable to move to tied the page, I used the function “Redirect attachment URLs to parent post URL”, and faced with this problem:
When I added an image to a post and published, if you click on the image, then be redirect to url (mysite.com/name-of-media-file), so if Link to attachment page has this form before publication.
When I edit the image in the post, it appears that the URL is not attachment page, but another page a Custom page with url to be written up, and when I choose link to Attachment page, everything works how it is necessary.

sorry for my English