Hi,
If you are going to use the 'wlan0' device then your kernel route table is not correct. As root from the cli;
Code:
~#route del default gw eth0 192.168.1.1
~#route add default gw wlan0 192.168.1.1
~# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 wlan0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
0.0.0.0 192.168.1.1 0.0.0.0 UG 1 0 0 wlan0
The route table should look like the sample above. Now try an ping as I suggested before.