After upgrading from Ubuntu 9.04 to 9.10 you might not get the sound from your Sound Blaster Audigy sound card.
Install GNOME Alsa Mixer
sudo apt-get install gnome-alsamixer
Click on the following link
Now open GNOME ALSA Mixer from Applications -> Sound & Video -> GNOME ALSA Mixer
Choose the tab: "SigmaTel..."
Turn on "Audigy Analog/Digital Output Jack"
That's it now your sound should work as normal