I'm using NextGen Gallery and would like to use the CDN to host the iamges. In the "Custom File List" I added "wp-content/gallery/*" and uploaded them with the button "Upload custom files" to the CDN (Amazon S3). Via the AWS Console I can see that all files are uploaded correctly.
Unfortunately the images on the page still link to local filesystem of the blog.
Did I forgot something? All over images from the media library are linked to the CDN, so the functionality seems to work. "Host custom files" is checked and all caches were cleared several times.