I'm having trouble with the CDN settings. I upgraded the Plugin a while ago and began to see these errors but didn't immediately see any changes on the front end.
I've finally had a look at the site and I can see that the images are no longer being displayed within the posts.
On further investigation I've found that when I test the connection between W3Total Cache and the CDN I'm receiving the following error.
Error: Unable to list buckets (S3::listBuckets(): [RequestTimeTooSkewed] The difference between the request time and the current time is too large.).
I've tried to generate a new Access and Secret Key but that hasn't made any difference. I also updated the SSL support to Diasabled with not changes.
I'm connecting though d3gjgrsrcarh41.cloudfront.net and everything is checked in the General CDN tab except for "Import external media library attachments".
Let me know what other information you need me to provide