Responding to this past post: Media Files Not Showing in Admin
When you delete an image it does not show up in the media editor/manager but well on the website ad in the media overview.
I just had the same issue and found that it has something to do after deletion and having weird characters in the file name. For example "Brackets" OR .JPG instead of .jpeg
The problem is only after you try to delete such a image.
That is all. Have a nice day Peeps.