使用Paperclip和IAM策略将文件上载到Amazon时拒绝访问

I am unable to get an upload working with Paperclip using an S3 IAM policy. I'm even having issues with direct jQuery uploads (no Paperclip). My scenario is as follows, I have an application that will have many sites. Each site will have it's own bucket and should only be able to access their own bucket, nobody else's. The I am unable to get an upload working with Paper