i figured it out. I was using wrong control bar to control the play/pause. the one I create by using "new ControlBar()" was a bit off the view on the stage while i do the test.
Is there any new version of REOPS? I am using the http://code.google.com/p/reops/downloads/list
BTW: the REOPSLib.swc seems not match the source. If i use the .swc, there will have some compilation error.
Where can i get the latest one?