AJAX chatbox not working in firefox

Ive been using an AJAX chat box on my blog (xboxsnippets.com) for ages
now but recently its stopped working when using firefox.

The chat window is ajax and in IE keepts to a scrolled window within the
wordpress widget, but when viewed in Firefox the windows present as a
long text box

Its easier to have a look

Now I did update the plugin the other day, but ive tried all previous
versions of the plugin and no joy. I also updated to wordpress 2.3, but
i cant find any info to say it's that.

One last thing - on my laptop that haas an older version of firefox, the
chat window works fine (im pretty sure)

Can anyone help me fox this glitch?

Cheers

Simon