Recently ran into something very strange. I was returning a structure to Flex from a ColdFusion Component and FLEX was receiving the structure keys as all UPPERCASE.

Take the following component.

<cfcomponent>
 <cffunction name="helloWorld" access="remote">
  <cfset var result = structNew() />
  <cfset result.msg = "Hello World!" />
  <cfreturn result />
 </cffunction>
</cfcomponent>

When called from Flex, the result will come back as

result.MSG

I guess ColdFusion doesn't see the case being used in the struct.key assinment.  If you want to retain the case of your structure keys you need to assign them like this..

<cfcomponent>
 <cffunction name="helloWorld" access="remote">
  <cfset var result = structNew() />
  <cfset result["msg"] = "Hello World!" />
  <cfreturn result />
 </cffunction>
</cfcomponent>

Creating your structures this way will retain the case of your keys and Flex will receive them in the way you have named them.