OK,

in order to get able to run xterm I installed OS2008HE on the N770 again and found out, that there are no root permission needed for ifconfig. You just have to use the full path

This is what ifconfig told about the wlan interface:

wlan0 Link encap: Ethernet HWaddr 00:14:A7:FE:73 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

So it seems that the interface is up but there is no transmission at all over it.

Yes, I also tried this but without success.

CU,
ReverZ