The problem with TWoC9 could be the resolution of the source.  Because the profile for the Expression Encoder is the same for all videos, version h264 codec, etc. For instance, are you having streaming issues with this video: http://channel9.msdn.com/Shows/This+Week+On+Channel+9/TWC9-Oct-7-2011

or only videos filmed like a screencast here: http://channel9.msdn.com/Shows/This+Week+On+Channel+9/TWC9-Nov-18-2011