When i click on the Insert Image icon, i should see a bunch of thumbnails, but the images show up as missing images.

When i click one of those 'missing images' to insert it, it does show up fine.

 

How can i fix the problem of the "Insert Image pop-up page" to actually display the thumbnails?

 

I tried changing the view by choosing the different dimensions; they always show with the IE x (missing image icon)