custom header uploaded but doesn't show up on site

my URL
http://www.ourlittlegardens.com/

I did: Cropped image to exactly this size-
Images of exactly 940 × 198 pixels will be used as-is.

theme is Weaver 1.7 but I have had this problem with a number of themes

tried jpeg, gif and png

I saw: no change on website after numerous attempts

I expected: to see my header & I didn’t

(I uploaded these images from my computer-just put them online for you to see)

http://i1129.photobucket.com/albums/m517/lightofatlantis/Light%20of%20Atlantis/Untitled-1copy.gif

http://i1129.photobucket.com/albums/m517/lightofatlantis/Light%20of%20Atlantis/Header1.jpg

http://i1129.photobucket.com/albums/m517/lightofatlantis/Light%20of%20Atlantis/Untitled-1copy-1.png

Thanks