 				return null;
 			var prefix:String = array[0];
 			var localName:String = array[1];
-			var uri:String = xmlContainingNamespaceInfo.namespace(prefix).uri;
-			return new QName(uri, localName);
+			var ns:* = xmlContainingNamespaceInfo.namespace(prefix);
+			if (ns)
+				return new QName(ns.uri, localName);
+			return null;
 		}
 
 		private function handleColumnDownload(event:ResultEvent, request:ColumnRequestToken):void

	import mx.utils.ObjectUtil;
	
	import weave.api.WeaveAPI;
	import weave.api.disposeObjects;
	import weave.api.registerLinkableChild;
	import weave.api.reportError;
	import weave.api.data.ColumnMetadata;
	import weave.api.data.DataTypes;
	import weave.api.data.IAttributeColumn;
	import weave.api.data.IColumnReference;
	import weave.api.data.IQualifiedKey;
	import weave.core.LinkableBoolean;
	import weave.data.AttributeColumns.GeometryColumn;
	import weave.data.AttributeColumns.NumberColumn;

				var keyQName:QName = getQName(result, featureTypeName);
				if (keyQName == null)
				{
					reportError('WFS response did not contain namespace of featureTypeName: ' + hierarchyNode.toXMLString());
					return;
				}
				var dataQName:QName = new QName(keyQName.uri, propertyName); // use same namespace as keyQName
