Installed, tried on an existing image in media library, get an error
Could not find /home/content/99/666777888/html/domainname/uploads/2011/04/image.jpg
This in spite of the fact that the image is accessible.
The address at which SmushIt is searching seems wrong. It should be looking for /home/content/99/666777888/html/domainname/wp-content/uploads/2011/04/image.jpg
I should mention here that /home/content/99/666777888/html/domainname/ is absolute path for http://domainname.com
http://images.domainname.com is mapped to /home/content/99/666777888/html/domainname/wp-content/uploads/ and WP retrieves images from http://images.domainname.com/