DirectShow multi panel

[sodiumpaul]

I am building an application that uses multiple panels in a Form to playback diffrent media sources. This all works well except that when a panel loads a new file from disc the other windows block for about a second. The code I'm using is pretty standard. I suppose I need to load the files on their own thread. How do I do this with the following DirectX solution?

FilterGraph.RenderFile(MediaFile);

try
{

//BasicAudio = (IBasicAudio)BasicAudio;
VideoWindow = (IVideoWindow)FilterGraph;
VideoWindow.Owner = (int)this.Handle;
VideoWindow.WindowStyle = WS_CHILD | WS_CLIPCHILDREN;