It seems that CaptureMouse is behaving differently in WPF and Silverlight, in that in the former one it immediately calls OnLostMouseCapture at a Visual, whereas in Silverlight it doesn’t get called if the element didn’t have the mouse capture already (btw, in Silverlight that method is at a UIElement – there is no Visual ...

Just added an issue to CSpeex project – http://cspeex.codeplex.com/workitem/18209 – with some fixes to make it compile for Silverlight 4 RC and higher (was for Silverlight 4 Beta), however still have issues with it not working correctly. Tagged: Audio, Capture, Codec, Demo, Silverlight, Speex, Webcam