problem seems to be solved, as someone mentioned above.
my original /etc/network/interfaces read like this:
auto lo
iface lo inet loopback
iface eth0 inet static
address 192.168.2.136
netmask 255.255.255.0
gateway 192.168.2.1
iface wlan0 inet static
address 192.168.2.136
netmask 255.255.255.0
g
Here are my /etc/network/interfaces :
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 192.168.2.136
netmask 255.255.255.0
gateway 192.168.2.1
iface wlan0 inet static
address 192.168.2.136
netmask 255.255.255.0
gateway 192.168.2.1
wireless-key ***
wireless-essid Br