Hello guys. I've been in trouble for several days. I've installed backtrack-5 r1 under the VirtualBox and when I'm trying to change the MAC address of my external rtl8187 I just can't do that. The way I'm trying is just the command "macchanger -r wlan0" after the "ifconfig wlan0 down", ofc. The problem is that the wlan0 won't get up. It says "SIOCSIFFLAGS Unknown error 132".

I managed to google it and I figured out that the sequence of commands:

rmmod rtl8187
rfkill block all
rfkill unblock all
modprobe rtl8187
rfkill unblock all

..is going to help me out. It actually did, and wlan0 successfully goes UP but the MAC address stays unchanged. Although I could beat 132 error, I still can not change my MAC address. Any suggestions?