W3 Total Cache and Amazon CloudFront issue

I wonder if anyone from here can help me resolve this issue?

I setup 8 subdomains to use with CDN Cloudfront and W3 Total Cache, but only 5 of them shows that they are using CDN with cloudfront, the remaining 3 does not show up any CDN (with cloudfront). I used W3 Total Cache to activate CDN and connect it to Amazon CloudFront. I am sure that I used the same procedure to setup CDN with W3 Total Cache and Amazon Cloudfront, but I wonder why the last 3 WP subdomain sites are not showing up. I am not using cname.

Using the CDN finder tool, the following 5 subdomains shows that they are using CDN with cloudfront:

CDN verification tool: http://www.cdnplanet.com/tools/cdnfinder/
http://ashburn.genesistreeservice.net
http://burke.genesistreeservice.net
http://centreville.genesistreeservice.net
http://fairfax.genesistreeservice.net
http://gainesvilleva.genesistreeservice.net

However the 3 subdomains below did not show that it is using CDN with cloudfront (although I activated the CDNs of these subdomains)
http://leesburg.genesistreeservice.net
http://reston.genesistreeservice.net
http://woodbridge.genesistreeservice.net

Please advise. Thanks!