It is possible that the drivers on your computer are outdated for the chat room. Mine were after I went to DSL.
So try and download sun micro systems java software at this address http://java.sun.com/j2se/
Click on the link download java vm and you should be set.
on the left hand side of the page. It is free and safe to use. I am running 1.4.0 and it is working fine.
Good luck