Trigger to URL works in HTML but not in SWF

I have added a trigger to a button which should open a link in a new browser window. After testing I found out that this only seems to work when you run the output as HTML, not as a SWF.

Tested in: IE9, Firefox 17 and Chrome 23.

Is this a known issue or do I do something wrong?

I have added a link to a page where you can see how I set it up.
Any suggestions to get it working in SWF too are appreciated.

http://www.e-learningalacarte.nl/examples/urltrigger/story.html

http://www.e-learningalacarte.nl/examples/urltrigger/story.swf