Media uploader loads full size image and slows down, please change to thumbnails.

[mnrtjeR]

The media uploader is really slow if you upload 1024 x 768 images, the reason for this is that the preview shows full size images.

Underneath here is a quick fix to speed up the media uploader to thumbnails.
Please change line 1333 in "wp-includes/media.php" from:

$attachment_url = wp_get_attachment_url( $attachment->ID );

to:

$attachment_url = wp_get_attachment_thumb_url($attachment->ID );