I have all my static content including images on Amazon AWS using S3. I have set up cname of format img.example.com. It has been working fine until Version 0.9.2.1 of W3TC but doesn't work after that. Since then I have stopped using this plugin.
However, my other static content like css and js files work fine.
If I disable the w3tc plugin, all my images and js/css files work which are similar to http://img.example.com/test.jpg. Upon enabling, i see all such image urls are of the form http://img.example.com/ but the js and css files work properly.
In firebug I saw an error for such img file requests -
XML Parsing Error: no element found Location: moz-nullprincipal:{470d926a-6ef7-2e49-9d24-af20036754e4} Line Number 1, Column 1:
^
To sum it up, when w3tc is enabled - the file name is truncated and html has only references to http://img.example.com/ instead of http://img.example.com/test.jpg. Appreciate any help on this.