I wanted to play with the Silverlight Streaming Server control that's part of the Live Tools for Visual Studio.
When i went to run my application I got the following error:
Sys.InvalidOperationExceptoin: DownloaError error#1001 in control 'SilverlightStreamingMediaPlayer1': AG_E_UNKNOWN_ERROR
I tried both the Dec CTP and the Feb CTP with the same error. Turns out you can't use a videos that were uploaded using the new "Manage Video" option, only applications.
So I've switched back to using videos uploaded as applications and it works a treat :)