I have updated to Mac OS X 10.6.3 and now my camera’s picture is blank

I have updated to Mac OS X 10.6.3 and now my camera’s picture is blank

Please test the webcam in an Apple program such as iChat (FaceTime), Photo Booth or QuickTime. If the webcam works normally there, the problem is with an Apple system file in 10.6.3 which can be fixed by upgrading to OS X 10.6.4 through Software Update.