I'm not able to join. IE prompts me to download an add-on installer when I click the chat link..but when I click the install button, windows blocks it because its unable to verify the publisher. 
your java is bad. I recommend firefox..or uninstalling and reinstalling your java.
Crap...I'm using a brand new laptop..its just 5 days old. Could it be windows 7?
maybe..asking 'could it be windows' is like seeing your house on fire and wondering 'was it el nina'?
Outta my expertise, amigo.