try that if not you will need to recompile the drivers and get the latest from http://linuxwireless.org/en/users/DownloadCode:
tar zxvf iwlwifi-6050-ucode-22.214.171.124.tgz
cp iwlwifi-6050-5.ucode /lib/firmware
I have the same problemme except my wireless card is
Network controller: Intel Corporation WiFi Link 1000 Series
The proper command to get monitor mode started on your wifi card is:
airmon-ng start wlan0
This should give you a new interface called mon0 so you can use it with airodump-ng
you also might not be able to do it as you could need elevated privs.
sudo ifconfig wlan0 down
sudo airmon-ng start wlan0
We do not support users adding repositories outside of the one's we supply to BT. Doing so has been known to cause issues of all sorts.