for 2 years, I've used my mac with firefox and really NO popups. Now I have a popup that keeps coming up. How do I go about detecting which website is bring it up? I don't usually notice it until I cycle through my windows because sneakily - it doesn't Pop to front of screen, it pops behind my webpage... sneaky buggers. my hunch right now is it is like imageshack or a website like that. I've been looking at posted screen shots recently and think it is something like that. Thanks for your tips!