Ok. I've just installed it. It changed nothing. Seems like it was already installed in this regard.
When I plug in the cam, a message pops up asking me if I want to download images from the cam. So I guess That the drivers for it are installed.
Anyway when I ask for spcagui (a webcam test utility), here's the output :
SpcaGui version: 0.3.5 date: 18 September 2005
video device /dev/video0
Camera found: ASUS TV-FM 7134
blah blah blah...
I still don't have any /dev/video1, only /dev/video0, in this case my TV tuner as you can see.