W3 Total Cache image files missing in CDN

W3 Total Cache is great but is really confusing me at the moment. I’m missing many image files on my pages and can’t seem to figure why some are transferred to the CDN (Amazon S3) but others are not. My unsuccessful transfer queue is empty but there are certainly a lot of images that did not make it to the CDN. I tried uploading host attachments again and my media library was cleared. It appears to be images/thumbs created by my theme but not all of them??? Also I’m using a child theme and W3 Total Cache doesn’t recognize or transfer the parent theme files. Please help.