Flex/Actionscript XML gotcha

I spent way too long troubleshooting this issue today. I was trying to initialize an XML object with some data from my actionscript object. Here is what I was doing:

private function someFunction(myObject:Identifiable) : void {
   var myXML:XML = <objectreference objectid="{myObject.id}">;
   myRoot.appendChild(myXML);
}

Then later on in my code I was doing an XPath query like so:

var list:XMLList = myRoot.objectReference.(@objectId=='foo');

Can you spot the problem? It took me way to long to notice the problem, which was obvious once I admitted to myself that I needed to actually use the debugger.

The problem was that I had double quotes around the expression {myObject.id}. The code should have been:

private function someFunction(myObject:Identifiable) : void {
   var myXML:XML = <objectreference objectId={myObject.id}/>;
   myRoot.appendChild(myXML);
}

Since having it incorrect with the quotes doesn't cause an error, I was really baffled on this.