Msn won't recognize my webcam

Hello,

I have a Toshiba Satellite A200 with in-built webcam. It works perfectly when I open it up normally but when I go to use it on msn the other persons works but mine has a big red cross in the box where the image should be. It used to work perfectly fine but now it has stopped. I have done the audio and video setup and it says everything is fine.

Could someone please help me!
Thanks!!