Auto connect to a wireless network (Ångström Linux)

I am using Ångström Linux on BeagleBoard-xM . I have installed a RTL8188SU USB Wi-Fi adapter and configured it properly. But it doesn't connect automatically even though I have marked the interface as auto in /etc/network/interfaces file. My /etc/network/interfaces file is seen below (only wlan0 settings pasted): auto wlan0 iface wlan0 inet static address 192.168.2.50 netmask 255.255.255.0 gateway 192.168.2.1 wireless_mode managed wireless_essid MY NETWORK ESSID wireless_key MY_PASS And here is the output of ifconfig command after system boot: root@beagleboard:~# ifconfig lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:24 errors:0 dropped:0 overruns:0 frame:0 TX packets:24 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:1632 (1.5 KiB) TX bytes:1632 (1.5 KiB) wlan0 Link encap:Ethernet HWaddr XX:XX:XX:XX:XX:XX inet6 addr: fe80::2e0:4cff:fe03:cbb1/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:241 errors:0 dropped:0 overruns:0 frame:0 TX packets:6 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) As you can see, there is no inet connection on interface wlan0. When I type ifdown wlan0 and ifup wlan0 consecutively, the wireless connection can be established successfully according to interface settings. The output of ifconfig after restarting wlan0 is shown below: wlan0 Link encap:Ethernet HWaddr XX:XX:XX:XX:XX:XX inet addr:192.168.2.50 Bcast:192.168.2.255 Mask:255.255.255.0 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:974 errors:0 dropped:0 overruns:0 frame:0 TX packets:22 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) I want my wireless connection to be established automatically on system boot (and preferably after replugging Wi-Fi adapter). Is there anything that I am missing to do so? **EDIT:** I have traced boot log and seen a message that is complaining about setting ESSID: Error for wireless request "Set ESSID" (8B1A) : SET failed on device wlan0 ; Operation not permitted. However, I haven't realized the source of the problem. After the system boot I can establish connection by restarting networking.