I have a local demo website which is protected by a
.htaccess to showcase to the customer. Anyways, in this installation the image preview in the CMS WYSIWYG editor is not working.
system.log there is an entry:
ERR (3): Warning: getimagesize(http://example.com/skin/adminhtml/default/ test/images/wysiwyg/skin_image.png): failed to open stream: HTTP request failed! HTTP/1.1 401 Authorization Required in /var/www/public/lib/Varien/Image/Adapter/Gd2.php on line 71