I set up an S3 bucket in a non-US region (Singapore). When I try to upload images to it, I get a 301 (Permanently moved) error from S3. Res
"Singapore" is not a valid "region" in the sense that you need, here:
AWS_S3_REGION = 'ap-southeast-1'
http://docs.aws.amazon.com/general/latest/gr/rande.html#s3_region
This may not be the only issue, but it should be one of the issues, at least.