CTRL+C + CTRL+V ---> MMS no Firefox

If you're sick of seeing "MMS is not a registered protocol" when trying to view streaming content, here's the fix (compiled from a few half-correct or half-clear descriptions from around the net).

I use Debian Linux with the KDE desktop, but this should work so long as you've got Firefox and Kaffeine installed. Mplayer would probably work in place of Kaffeine.

(1.) Open Firefox, type "about:config" (no quotes) in the address window, and click enter.
(2.) Right click on the window and choose , then from the pop-up menu that appears.
(3.) In the first pop-up box, enter: "network.protocol-handler.app.mms" (no quotes, and it might just be easier to cut 'n paste this into the box).
(4.) In the next pop-up box enter the path to Kaffeine (e.g. "/usr/bin/kaffeine").
(5.) Now, click in the main window again but choose
(6.) In the first pop-up box, enter: "network.protocol-handler.external.mms"
(7.) In the second pop-up select .

FONTE: http://www.cinlug.org/node/316