I was checking my website statistics and particularly the 404 errors. I found the following one: [404]/wp-admin/images/screen-options-left.gif
I investigated and found out that it came from wassup css:
.wassup-menu-link {
float: right;
background: transparent url(images/screen-options-left.gif ) no-repeat 0 0;
font-family: "Lucida Grande", Verdana, Arial, "Bitstream Vera Sans", sans-serif;
height: 22px;
padding: 0;
margin: 0 6px 0 0;
text-decoration: none;
text-align:center;
}
Apparently, this gif file is no longer present in WP 3.0 and up.
See here: http://wordpress.org/support/topic/plugin-seo-ultimate-404wp-adminimagesscreen-options-leftgif
