Macbook Cam Issues

I am posting this hoping that others will come to my aid. I have an macbook with an internal isight camera. The camera works in photo book but will not work with any other internet applications (yahoo im, skype, tn chat room). The computer does not recognize the camera except that it will turn on in photobook. I have tried using different browsers such as (safari, firebox, opera) with no luck.
My camera used to work in safari (in the tn chat room) and would work okay on all of my IM programs. If anyone knows what I can do to get it working again, PLEASE HELP!

Thanks!

-EloquentOne