How do I fix iChat Theatre black screen problem?

Hi,

I am having trouble sharing through iChat Theatre. Every time I drag something, whether it be a photo or video to the window, it goes through, but the ichat theatre window becomes black. Specifically, when I drag a video in, the video will play with sound but no visual, a black screen just comes up. Can anyone help me solve this problem? It would be much appreciated.

Thanks in advance,