Wilma, I suspect that the problem is caused by your “Java” cache – which is what remembers your last user name for example. This has occasionally happened to me and my cure is to clean out all the temporary internet files & internet & Java cache (using Window Washer – see above).
This enables me to start over with a clean slate.
The other issue that I’ve come across is where a user fails to “log out” when they leave the chatroom and simply closes their browser. This can cause an issue where the system thinks that you are still logged in and it takes ages and ages for the chatroom software to purge yuor user name from its ‘memory’.