ubun2^beta

I recently installed firefox 3.5 but when i launch from Applications -> Internet -> Firefox Web Browser, it is still launching firefox 3.0 instead of the newly installed. Please suggest

Firefox 3.5 browser just got released  and i tried
sudo apt-get install firefox
and also
sudo apt-get install firefox-3.5
but no luck. Still i see only firefox 3.0 browser installed on my machine. 
Please help