This has to be the worst upgrade ever...!
Harsh words from me, I love firefox both for PC and Mac, but this is crap!!!

Java doesn't display properly!
SSL certificates and encryption fails on load!

Which are to major things that I normally use my firefox fore, since that covers Safari's shortcomings...

the above problems cause the browser to crash, meaning use of "forcing quite"

SSL problem might be Java related... not sure about that...

BUT my advice is stay well clear of this upgrade...