The page is waiting to finish loading. It makes a request and then waits. The problem seems to be that the browser is not displaying the data once it gets it. I'm curious why that is. It should flag as an error in the firebug console (first tab.) If you reload the page with that console open, it should tell you if there was an error.

I just noticed that FF seems to have it's own, built in version of firebug now too. Also has a console.