Amazon S3 w/ W3 Total Cache conflicting with Prosites on a shared enviornment.

I use mediatemple hosting and have multiple hosting accounts in a shared environment using the same IP address. Site A is a WPMU site with prosite installed and is the main site in the hosting enviornment, Site B is a WP site with W3 Total Cache set up using Amazon S3.

The bucket is set up so that cdn.siteb.com has a CNAME change pointing to the bucket. So cdn.minutetillsix.com is pointing to cdn.minutetillsix.com.s3.amazonaws.com. This set up is working correctly for all theme files and all other files except for on the home page, media library image files are not coming up. When I debug with firebug for some reason there are multiple requests coming up for potential new sites for prosites.

So for instance
http://cdn.minutetillsix.com/wp-content/themes/generate/images/blue/generatebox-heading.png will work correctly but a featured image on the homepage is triggering a phone home to http://webento.com/wp-signup.php?new=cdn.minutetillsix.com.

Here are both sites I am leaving the CDN on for now for debugging purposes. I have been trying to debug the reason and am stumped on how to fix it. Any and all help would be appreciated.

Site B: minutetillsix.com
Site A: webento.com