SWFObject IE7/IE8 error ExternalInterface

What steps will reproduce the problem?
1. Create a SWF with the next code:
ExternaInterface.call('ready');
2. Open IE7/IE8 on Vista.
3. Then embed the SWF with SWFObject.embedSWF (the first time is probably that 
it works, the next times it doesn't)

What is the expected output? What do you see instead?
The javascript throws an error pointing to this line:

function __flash__addCallback(instance, name) {
  instance[name] = function () { 
    return eval(instance.CallFunction("<invoke name=\""+name+"\" returntype=\"javascript\">" + __flash__argumentsToXML(arguments,0) + "</invoke>"));
  }
}

What version of the product are you using? On what operating system?
SWFObject 2.2, IE7/IE8, Windows Vista Business Edition

Please provide any additional information below.

Original issue reported on code.google.com by asakon28 on 4 Aug 2011 at 12:00

Merged into: #578

google-code-export / swfobject

SWFObject IE7/IE8 error ExternalInterface #584