Mash up? the subtitled MIX 08 keynote video

I wrote a Silverlight app to watch the MIX 08 keynote video with a subtitle.
UI of the app is derived from Expression Media Encoder.

the mechanism is simple: after the video is opened, TimelineMarker objects are dynamically created and added to MediaElement.Markers property.
and in a MarkerReached event handler, the caption of the player is set to the value of TimelineMarker.Text.
I tagged all the timings manually. (yes, I took advantage of another app I wrote.) If only I had a speech recognition system.

EDIT:Actually, there is a trick.
all videos are hosted on "msstudios.vo.llnwd.net" domain and you can't dynamically added TimelineMarker objects. (it's a cross domain restriction, I think.)
So, I put an asx file at a server. I doubt that it works on Mac.
A problem is that a browser occasionally freezes when closing for an unknown reason. Can anybody fix it? EDIT: fixed. a WMV file I chose was wrong.