Bug 1341 - wlan0 disappears after running for a while

remove driver and install again causing wlan0 authenticated and associated (don't need reset system) do this:
modprobe -r iwl4965 (verify by modprobe -l | grep -i iwl4965)
modprobe iwl4965
------------------------upgrade driver iwlwifi.1.2.23 see if it fixes the problem.
tar xvf iwlwifi.1.2.23
cd iwlwifi.1.2.23
make
make install