This post is more than 2 years old.
Yesterday I was helping a ColdFusion user who is just getting into Flex. He kept getting this error:
[RPC Fault faultString="[MessagingError message='Unknown destination 'Coldfusion'.']" faultCode="InvokeFailed" faultDetail="Couldn't establish a connection to 'Coldfusion'"]
This was his first attempt trying to hook Flex 2 into ColdFusion and he wasn't getting anywhere. His code looked ok to me:
<mx:RemoteObject id="cfService" destination="Coldfusion" source="flexbtb.cfc.myService" />
But then I noticed something. He had "Coldfusion", not "ColdFusion". Turns out the destination value is case sensitive. Just one more example of something us ColdFusion developers have probably gotten a bit lazy with - case sensitivity.