SSL Resource On Non-SSL Page and Invalid Content for Image

Hi,

I'm trying to improve performance for my site.
I just performed a test on Zoompf and here is what it's saying :

SSL Resources On Non-SSL Page
- Critical impact
- Easy to solve

Affected URL :
http://www.oreille-malade.com/wp-content/plugins/buddypress-activity-plus/css/external/loading.gif

Issue Summary :
This response contains a hyperlink to an image, JavaScript file, CSS file, or page resource using a encrypted SSL channel. Since this page was not served using SSL, the browser will need to contruct a new encrypted SSL channel to the web server. It is very expensive to construct and maintain an encrypted connection and in this context it is completely unecessary as the base page was not served using encryption. You should replace this hyperlink with a path relative or protocol relative hyperlink. This will drastically improve page load time while decreasing server load.

EDIT :
Zoompf pointed out another problem for the same url :

Invalid Content for Image :
- High impact
- Easy to solve

Issue Summary :
The resource at this URL is not an image. However it was referenced from another resource as an image either using a <IMG> tag or as a CSS background image. This is usually caused when the image is missing and the web server instead returns an error page or another resource which is not a valid image.

Affected URL :
http://www.oreille-malade.com/wp-content/plugins/buddypress-activity-plus/css/external/loading.gif

Another one, of course for the same url :

Missing Resource (Background Image) :
- High impact
- Easy to solve

Issue Summary :
This background image is missing but there are references in the style information to it. This could be a typo in the URL, but more likely the design of the has changed and the style information that references the missing background image is not longer used. This means can remove the CSS rule or rules that references and reduce the size of your CSS files.

Affected URL :
http://www.oreille-malade.com/wp-content/plugins/buddypress-activity-plus/css/external/loading.gif

I checked and this url is indeed a 404.

Could you have a look, please ?

Best Regards,
Laurent