We've been using DreamPress at http://www.radiosurvivor.com almost since the service started, and we continue to have persistent problems with images not loading intermittently. These are all images uploaded and resized using the WordPress interface, and there's no one image that refuses to load all the time. It's unpredictable.
We have contacted DreamHost support numerous times, and most recently they say they can't recreate the problem, even though it persists.
To troubleshoot we've turned off all unnecessary plug-ins, and double-checked them against those that don't play nice with Varnish, just to be sure. That made the problem less worse, but it has not gone away.
As well, we still experience 503 Varnish cache server errors regularly when posting, not matter how often we flush the cache manually.
We're getting to the end of our patience, particularly with the image problem. I understand that it's intermittent, and therefore not very easy to recreate. Yet, I experience it at least 40% of the time -- something that has been corroborated by other users across different browsers and OSes.
Any help would be appreciated, since it's making us reconsider choosing DreamPress.