Curl error when connecting to S3 using Snapshot 2.5

I am getting the following error when testing a connection the my S3 destination.

Sending file to: Bucket: vpcsnapshots: Directory: snapshots/Error: Send file failed :cURL resource: Resource id #445; cURL error: necessary data rewind wasn't possible (cURL error code 65). See http://curl.haxx.se/libcurl/c/libcurl-errors.html for an explanation of error codes.