S3 Storage upload and download error

What permissions do you have on the user you are using to upload and download? I do uploads all the time and mine works fine using a python script.

Here's my JSON for the policy of the user I use to do this. Maybe this will help. You may not need ListBucket or ListAllMyBuckets. I need them, though, because my script uses them.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "VisualEditor0",
            "Effect": "Allow",
            "Action": [
                "s3:PutObject",
                "s3:GetObjectAcl",
                "s3:GetObject",
                "s3:ListAllMyBuckets",
                "s3:GetObjectAttributes",
                "s3:ListBucket",
                "s3:PutObjectAcl"
            ],
            "Resource": "*"
        }
    ]
}

What client are you using to access S3, and how is it getting AWS credentials? Are the credentials still current?