Generates only urls?

Hello,

I’m testing “the plugin that I’ve been waiting for so long” on a locale website, but at this time, all I have is that nothing has changed: wp still generates thumbs for every picture in every size…
(All I do is uploading pics to the media library)

After having uploaded, I removed the generated pictures, and went to the media library; then it generates the images at the sizes requested by the media library (and only those ones). Which is cool, since it’s doing its job, but only in backend, and only after having removed the generated pictures. When I go to the frontend, urls are generated but no pics.

Any idea?

(I’m using wp_get_attachment_image_src)