Gray shadow around images at the blog page

Hi!

Have have trouble to remove the gray shadow around images at the blog post page. I have managed to remove the gray shadow on post images with:

.entry-content a img,
#attachment-nav a img {
padding:0px;
box-shadow:0 0 0px;
background:#FFF;
border:#EEE 0px solid;

}

Look at this picture
http://goo.gl/VTbq1 to see the gray shadow at the red arrow.

Or you can see my page live at:
http://martin.hostit.se/blogg/

Someone have a solution for this problem?