The intel ipw3945 is already loaded on BT3. Along with the ipwraw modules.
I use the command:
modprobe -r iwl3945 (this will unload iwl3945)
modprobe ipwraw (this will load ipwraw for packet injection)
once you get done with that then do
modprobe -r ipwraw (to unload packet injection)
modprobe iwl3945 (to load the original mod)
also in case you didnt know you cant surf the internet while in monitor mode.
Let me know if you get it working.