Stephen John Smoogen <smooge <at> gmail.com> writes:
From my research to use the SHA-2 in TLS requires the user and server to be both able to talk TLS-1.2. From what I found at wikipedia (http://en.wikipedia.org/wiki/Transport_Layer_Security) Firefox does not support 1.2 (only Opera and IE8 do).
It's being worked on, at least: