Maybe first, open a terminal, and type (copy and paste..... saves typo's..... just remember the $ is a prompt so don't copy that.):-
Read through the output and see if your card is recognised, if it is there, then try:-
This might give you a clue as to whether you have the firmware or if there is problems loading it.
If your card is recognised, you can probably skip the first part of the solution, and just get the firmware if you need it.
If not you will have to follow the entire solution....
First install mercurial... from synaptic or:-
Then change directories:-
apt-get install mercurial libncurses5-dev
Then begin the solution
Also after this line ( $ perl -p -i -e 's/FIREDTV=m/FIREDTV=n/' v4l/.config.) Where it says "edit as needed" escape or tab through to the finish... it should tell you which is correct!
Then continue with the rest of the solution.