NYC Wireless controls the router. Maybe I should forward this post to them, if I
can.

I know I would never know, that is why I thought the Ghost pop-up FireFox was
suspicious. Why would it come up and then vanish like that?

I've had similar experiences on Windows and other Linux installations that ended
up with so many copies of my desktop opening on my slow system that it was
rediculously apparent. Seems like some of them or maybe all of them also opened
the Ghost browsers that vanished.