When you load content from another domain and you want to use BitmapData, then you always have to load a policy file (crossdomain.xml) from that other domain. What I discovered today is that you have to do this for ALL the content you’re loading, otherwise the BitmapData just doesn’t work. Even if it’s content you don’t want to use for the BitmapData, you still need to load the policy file. It took me quite a while of debugging to figure this out.

This is our current setup. Every server has its own domain.

The other thing I learned today is a small trick to remove the Warning in your logs. Jeffry Houser explains it in his post Fixing your CrossDomain.xml File.