playerUpdateNewAsset javascript handle not working?

Im trying to implement the callback in the kdp for when the player is playing a mix and the media asset is changed/updated (roughcut with multiple assets in it)
And the kdp is giving me a :
"Error: Error #1023: Stack overflow occurred.
at flash.external::ExternalInterface$/_objectToJS()
at flash.external::ExternalInterface$/_toJS()"

My Js code:
onKdpReady()
{
getEmbededFlashElement("KDPHolder").addJsListener("playerUpdateNewAsset","playerUpdateNewAssetFunction");
}

function playerUpdateNewAssetFunction()
{
alert("assetChanged");
}

Ideas? or, how many params does the playerUpdateNewAsset handle expect?

Can anyone shed some light?

Thanks,
---Jeff