You need uninstall logitech driver then download new driver. Check yahoo or oovoo's video capture device: Make sure pick logitech pro 5000 in list. I dont have yahoo or oovoo software with me right now but I am pretty sure video capture device is not correct.
I think it is the webcam application which is left open, it needs to be closed, if you want to use the webcam to have a chat on oovoo or any video conversation applications.
every time i try get webcam on yahoo or oovoo and cam wont work.. i dont undy why.. but i take pix with cam test and it worked.. but not webcam.. how come??? my webcam is Logitech pro 5000 and 2 yrs old.. pls discuss and tell me what to do with this???