Boy Temmu...something sure doesn't seem to want to allow you in the LzD Chat Room

I can get in using the Java applet w/ same as you: IE6 & FF2 & Java JRE 1.6
According to Java article at MozillaZine:
BrowserSpy - Java Information at gemal.dk will tell you whether or not Java is installed and the JRE version, even if Java is currently disabled in the browser (you can disregard any of the "Could not read" notations listed under the "Java using the applet tag:" heading).
http://kb.mozillazine.org/Java <<<Link to BrowserSpy-Java Info at the bottom of page :
Testing Java3-4 ppl posted same errors as you with differing opinions as to why. See if any fit?
http://www.ld4all.com/forum/viewtopic.php?t=8329&postdays=0&postorder=asc&&start=45As far as Trillian, if you are using the latest version 3.1.7.0, yup, ditto what
GR@PH;<'S says...IRC should be there.
Twas a bit misleading in the install cuz it offers you a variety a "options/plugins" to choose. I de-selected the Ask Toolbar and the Weather thingy. The plugins offered are these:

You don't see IRC listed and, of course, I saw ICQ and thought it must be a typo

<Well, no wonder Corrine's screenshots don't match mine as I am trying to fill in the info for IRC in the ICQ boxes

>
Where
GR@PH;<'S is pointing is how I got it configured to "Add a new connection"...once you tick that IRC box in the Plugin page, it then shows up when you choose Add a new connection.