There has been some major changes in Firefox 3 regarding to how the Chinese text are displayed on the screen. NJStar Communicator was having problem converting Simplified Chinese to Traditional Chinese, and vice versa. After some hard work, we found the right solution for the problem. I am happy to report that the case is now closed. You can now upgrade to v2.73.8618 if you are using Firefox 3.
 
Free Download:  NJStar Communicator 2.75.9518 Shareware Version 
Free Upgrade:   NJStar Communicator 2.75.9518 Upgrade for Registered Users