ActiveRecord在Heroku上错误地加载二进制字段，在OSX上很好

I have a rails 3.1 app that stores images in a binary field in a postgresql database (I am aware of potential issues with storing images in a database, but have to do so for now). Everything works fine locally in development mode and specs on OSX, but all images are broken in the app deployed to Heroku. I've verified that the data in the database is correct by pointing my local machine at the same database that the heroku instance uses, and all images displayed correctly.I have a rails 3.1 app that stores images in a