Probably not connected, but I've come across a couple of websites recently that don't work in Firefox for "no apparent reason". It often turns out to be some hidden (iframe) content which requires script to run that NoScript is blocking, but which doesn't show up on the menu bar NoScript menu. Of course, I don't have NoScript on other browsers. It's only when you dig around and find the correct site to "allow" that the whole thing springs into life.
I first met this kind of symptom on shopping sites, which use Arcot or Sagepay or Worldpay or similar in a "hidden" window to verify your card details. Unless you already have those sites allowed the transaction will fail.