Just wanted to warn existing users that firefox has changed its cookie handling capabilities which might result in shoutbox giving you unauthorized messages. This only effects bleeding edge of firefox trunk releases

So if you are on ff2 please ignore.
For now, tested on tonights trunk release, you have to change your cookie preferences to allow 3rd party cookies to send data.
To do so do this:
type
about:config in the url bar.
do a filter search for
cookie
Change the default behaviour of
network.cookie.cookieBehavior from 1 to 0. 1 is default which blocks all third party cookies.
Submitted bug report and the issue has been solved so hopefully the RC release of ff will not have this problem.