I am using Firefox and there seems to be an issue using the chat with tabbed browsing. If I open up the chat applet in a new tab then whenever I switch back to one of my other tabs the menus and the chat boxes show up through the tab I am looking at, and anything I type is put into the chat box.
Yes, I have no problem using the chat facility, the problem is that the chat applet wants me to use it when I am trying to do something else on a different tab. So if I am trying to write a replying post on the message board it tries to put it into the send field of the applet, for example.