Nope. I changed nothing before this happened.....unless there is something in Firefox that did so automatically....when I loaded it through Firefox, I didn't get the menus at the top of the screen, nor my background....everything was in white.
The URL I went to is here....
http://webmessenger.msn.com/
As far as I know, I've not got a naughty version...it came with the machine....I've also had an MSN messenger update.