Here there is my experience about the installation of Hauppauge WinTV-NOVA-T-Stick on UBUNTU 12.04.
1) Connect WinTV-NOVA-T-Stick to the PC, ATTENTION: is necessary an USB 2.0
2) Install: KAFFEINE, that we will use to see the digital TV for do this uses:
Ubuntu Software Center and search and install Kaffeine (see below)
ATTENTION: The first time that run KAFFEINE you must select: Configure Television and set AUTOSCAN (see below)
3) Install the media player library (from the terminal) using the command:
sudo apt-get install libxine1-all-plugins
At this point you are done – watch the TV 🙂