After a few months I finally resolved my Fix Channel Mode : -1 on Aircrack-ng with Ubuntu 11.04.
As far I concern most of the time i been using (Monitor Mode) mon0 as the interface but actually we can set and used wlan0 in monitor mode as well.
Sorry I bit slow in this resolution even this might be resolved by others long time ago.But its keep bugging me to find a solution for it.
Below are the step taken :
1) If you already enable mon0 kindly turn it off
- airmon-ng stop wlan0 / mon0
2) After that you need to follow this instruction :
a) ifconfig wlan0 down
b) iwconfig wlan0 mode managed
c) ifconfig wlan0 up
d) iwconfig wlan0 channel (Channel of the Victim AP)
e) ifconfig wlan0 down
f) iwconfig wlan0 mode monitor
g) ifconfig wlan0 up
3) You may skip ( a / b ) but better to do it in-active mode.