Now on to the fix:
First, we need to install gnome-alsamixer
If you like the terminal, type
sudo apt-get install gnome-alsamixer
...Or use Ubuntu's software center or your favourite package manager (such as Synaptic) to get that step done.
Then, find and run it:
Now choose the tab labelled something like "SigmaTel…" and
Enable/check the box beside the text "Audigy Analog/Digital Output Jack":
...And now your sound should be working again!
Credits go to my source: http://bit.ly/FLbY