rtl8187 error in BackTrack 4 R2

I haved this problem since the BT4 r1 and i get the solution for this ERROR :-

1. modprobe rtl8187

2. rfkill block all (in BT4 R1 doesnt have must install its first)

3. rfkill unblock all

Now you can try to put your wireless card in monitor mode

happy hunting....................