Hi there,
I think that we are having the same issue with the 404 error.
We loaded DreamPress yesterday and the CDN (DreamSpeed) this morning.
I began the upload of existing images to the CDN by clicking the “Upload Existing Media” button which worked fine. There were something like 218 images. It has not gotten to image 130 (130 files can be migrated) and when you click the “Uploading Existing Media” button it goes straight to a 404 redirect.
Any help would be most appreciated.
Matt.