I have an external monitor connected to my MacBook Pro. Until yesterday, my external Logitech QuickCam Vision Pro for Mac worked perfectly on Yahoo Messenger and Skype. Suddenly, Messenger can't find the Logitech cam or the built-in iSight cam. They both show up on PhotoBooth and iChat (which I don't use because my friends are all on PC's and Yahoo). On Skype, the program tells me the camera is being used by another program but as far as I know all my programs that use a camera are closed. So far I have reinstalled Snow Leopard, done a permissions check, reset the PRAM and SMC but no luck. Does anybody out there understand this and can give me a solution? Thanks.