Thanks for you help Jake, but i had already tried this one ...
Actually, the kext is working, and my card recognized
After digging a little more , the problem was not the kext, but that i was getting a 169.254.... IP address !
So , googling this lead me to :
1 - Reboot, disable NIC, -f
2 - Reboot, enable NIC, -f
And now i have the network card with a good IP address !
So problem solved i guess...