To prevent them use the code as follows and stoping the updater:

—————-

private function checkForUpdate():void
{
// Find the current version so we can show it below
setApplicationVersion();
// Server-side XML file describing update
appUpdater.updateURL = ApplicationController.UPDATE_URL;
// We won’t ask permission to check for an update
appUpdater.isCheckForUpdateVisible = false;
//versions detection
appUpdater.isNewerVersionFunction = compareVersion;
// Once initialized, run onUpdate
appUpdater.addEventListener(UpdateEvent.INITIALIZED, updateInitializedHandler);
// If something goes wrong, run onError
appUpdater.addEventListener(ErrorEvent.ERROR, updateErrorHandler);
// Initialize the update framework
appUpdater.initialize();
}
private function compareVersion(currentVersion:String, updateVersion:String):Boolean
{
//stop showing default updater dialogbox
appUpdater.cancelUpdate();
//compare versions
if(currentVersion != updateVersion)
{
// set an information text for the user
var dialogCopy:String = “An updated version ” +updateVersion + ” is available. Click here to download.”;
// or directly display a download prompt
//var urlReq:URLRequest = new URLRequest(“”);
//navigateToURL(urlReq);
}

return false;
}

Is it possible to update using appUpdater.updateURL ??