Flex 4 wont recognise flash.events.UncaughtErrorEvent

Question

test.mxml:

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" creationComplete="init()" x="0" y="0" width="703" height="609"  xmlns:ns1="*" >
<mx:Script>
<![CDATA[
import flash.events.*;
// stuff
private function onUncaughtError(e:UncaughtErrorEvent):void {
//Do Stuff
}

This gives: apitester.mxml 1046: Type was not found or was not a compile-time constant: UncaughtErrorEvent. /apitester/src line 35 Flex Problem

According to Adobe it is available in flex and Air.

The Flex 4/Eclipse build path shows:

Flex 4.0

1. playerglobal.swc
2. textLayout.swc
3. osmf.swc
4. framework.swc
5. spark.swc
6. sparkskins.swc
7. rpc.swc
8. datavisualisation.swc
9. flash-integration.swc
10. flex.swc
11. utilities.swc

Any ideas?