I'm running 1.0-beta2 on a test server and browsing it with Firefox 1.5.0.4. It doesn't work, I just get the chat window with nothing appearing inside it, and the Javascript console gives two errors:
"Class is not defined" on line 16 (the line here is, "var pfcI18N = Class.create();") and
"pfcClient is not a constructor" on line 2193 ("var pfc = new pfcClient();")
It looks like everything is the same as the demo on the site (which works fine on the same browser), it just gives me these errors.